#$%^&*AU2015202854A120150618.pdf#####ABSTRACT The present invention relates to a method of diagnosis and therapy of cancers expressing the HER2 receptor. The invention provides antibodies or fragments thereof that recognises an epitope of a HER2 receptor truncated form, said epitope being 5 defined by a sequence included in SEQ ID NO: 2. The invention also provides a method of cancer diagnosis, which comprises the detection of the presence of the HER2 receptor truncated form consisting of the amino acid sequence SEQ JD NO: 1 in a patient sample.