OACP4 C was established from a primary tumour located in gastric cardia of a 55 year-old Caucasian male. The patient showed lymph node involvement with pleural metastases. OACP4 C was found to be tumourigenic in NMRI (female nude mice or NOD-SCID mice. The Y chromosome could not be detected in this cell line by short tandem repeat (STR)-PCR analysi. It is a known phenomenon that due to the increased genetic instability of cancer cell lines the Y chromosome can be rearranged or lost resulting in lack of detection.