Of 19 candidates, the cloned and expressed recombinant SnuCalCp03-propeptide (rSnuCalCp03-propeptide) showed a low nanomolar Ki value of 2.3 ± 0.2 nM against cathepsin L. A significant inhibition of tumor cell invasion was observed with H1975, HT29, MDA-BM-231, PANC1, and PC3 with a 76, 67, 67, 63, and 79% reduction, respectively, in invasion observed in the presence of 400 nM of the rSnuCalCp03-propeptide. This evidence concerns the gene CTSL and neoplasm.