In addition, stefin B was also suggested to contribute to the resistance of melanoma cells to TRAIL-induced apoptosis, however, the inhibition of cathepsins L and B was found not to be important in this process, and stefin B was suggested participate in the process by preventing the proteasomal degradation of FLIPL, by an yet undefined mechanism (Yang et al., 2010). This evidence concerns the gene CTSL and melanoma.