PKM and gastric cancer: PKM2 mRNA and protein expression were also examined in a series of GC cell lines (NCI-N87, BGC-823, SGC-7901, AGS, SNU-1, SNU-16, MKN45, KATO III, MGC-803 and MKN28) and normal gastric mucosal cells GES-1 (Fig. 1D and E).