tokens: By primer extension analysis to discriminate two transcripts , we found that the levels of PAFR transcript 1 ( leukocyte-type ) , but not PAFR transcript 2 ( tissue-type ) , are upregulated by PAF as well as by 12-O-tetradecanoylphorbol-13-acetate ( TPA ) in the human stomach cancer cell line ( JR-St cells ) which expresses both functional PAFR transcript 1 and PAFR transcript 2 endogenously .