Expression of E-cadherin (CDH-1) [19], LI-cadherin (CDH-17) [20], MUC5AC[21], MUC6[21], MUC2[21], vimentin[22], CTSD (cathepsin D) [23], [24], CTSE (cathepsin E) [23], [24], CTSB (cathepsin B) [25], CTSL (cathepsin L) [25], and GAPDH (internal control) genes were evaluated by RT-PCR in 20 GC lines together with the 12 cancer cell lines derived from other organs (Figure 1A). This evidence concerns the gene CTSL and gastric cancer.