SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16 OF
THE SECURITIES EXCHANGE ACT OF 1934

13 July, 2006

Cambridge Antibody Technology Group PLC
(Translation of Registrant’s Name Into English)

Milstein Building, Granta Park, Cambridge, CB1 6GH, England
(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-

Form 20-F ____X____ Form 40-F ________

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1):

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7):

Indicate by check mark whether by furnishing the information contained in this Form, the registrant is also thereby furnishing the information to the Commission pursuant to Rule 12g3-2 (b) under the Securities Exchange Act of 193

Yes _________ No ____X_____

If “Yes” is marked, indicate below the file number assigned to the registrant in connection with Rule 12g3-2 (b): 82-___________

EXHIBIT INDEX

This filing contains the following exhibits.

EXHIBIT DESCRIPTION

99.1 Holding(s) in Company dated 13 July 2006

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Date: 13 July, 2006 Cambridge Antibody Technology Group PLC

                                                                                                                                                                 By: /s/ John Aston
                                                                                                                                                                 Name: John Aston
                                                                                                                                                                 Title: Chief Financial Officer

EXHIBIT 99.1

NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Name of company

Cambridge Antibody Technology Group plc

2. Name of shareholder having a major interest

Wellington Management Company

3. Please state whether notification indicates that it is in respect of holding of the shareholder named in 2 above or in respect of
a non-beneficial interest or in the case of an individual holder if it is a holding of that person's spouse or children under the age
of 18

Non beneficial

4. Name of the registered holder(s) and, if more than one holder, the number of shares held by each of them

Not known

5. Number of shares / amount of stock acquired

N/A

6. Percentage of issued class

N/A

7. Number of shares / amount of stock disposed

Not known

8. Percentage of issued class

Not known

9. Class of security

Ordinary 10 pence shares

10. Date of transaction

Not known

11. Date company informed

12 July 2006

12. Total holding following this notification

Not known

13. Total percentage holding of issued class following this notification

Not known

14. Any additional information

The Company has been notified that Wellington Management Company no longer have a notifiable interest in the ordinary shares of the
Company

15. Name of contact and telephone number for queries

Justin Hoskins, 01223 898589

16. Name and signature of authorised company official responsible for making this notification

Adrian Kemp, Director

Date of notification

13 July 2006

The FSA does not give any express or implied warranty as to the accuracy of this document or material and does not accept any
liability for error or omission. The FSA is not liable for any damages (including, without limitation, damages for loss of business
or loss of profits) arising in contract, tort or otherwise from the use of or inability to use this document, or any material
contained in it, or from any action or decision taken as a result of using this document or any such material.

NOTIFICATION OF MAJOR INTERESTS IN SHARES

1. Name of company

Cambridge Antibody Technology Group plc

2. Name of shareholder having a major interest

Credit Suisse Securities (Europe) Limited

Non beneficial

4. Name of the registered holder(s) and, if more than one holder, the number of shares held by each of them

Not known

5. Number of shares / amount of stock acquired

N/A

6. Percentage of issued class

N/A

7. Number of shares / amount of stock disposed

Not known

8. Percentage of issued class

Not known

9. Class of security

Ordinary 10 pence shares

10. Date of transaction

Not known

11. Date company informed

12 July 2006

12. Total holding following this notification

Not known

13. Total percentage holding of issued class following this notification

Not known

14. Any additional information

The Company has been notified that Credit Suisse Securities (Europe) Limited no longer have a notifiable interest in the ordinary
shares of the Company

15. Name of contact and telephone number for queries

Justin Hoskins, 01223 898589

16. Name and signature of authorised company official responsible for making this notification

Adrian Kemp, Director

Date of notification

13 July 2006

END

CAMBRIDGE ANTIBODY TECHNOLOGY GROUP PLC 6-K