A method of treating a patient having a cancer in which HER2, HER4, FGFR1, EPHA2 and/or FGFR3 is upregulated and/or in which HER2, HER4, FGFR1, EPHA2 and/or FGFR3 mediated-signaling is upregulated, the method comprising administering to the patient a compound comprising or consisting of an OPCML polypeptide (SEQ ID NO: 1), or a fragment thereof which comprises at least one Ig domain of OPCML, or a variant thereof having at least 90% sequence identity with the OPCML polypeptide or the fragment thereof, or a nucleic acid molecule which encodes the OPCML polypeptide or fragment or variant thereof.
