PTGS2 and neoplasm: Examination of stained tumour specimens revealed that 81% (22 out of 27) of the tumours expressed FasL and 96% (26 out of 27) expressed EP1, whereas COX-1 protein was detected in the neoplastic cells of 88% (22 out of 25) of tumours and COX-2 in 85% (23 out of 27) of tumours.