FAS and melanoma: Similarly, a siRNA specific for Mcl-1 was proven to be able to sensitize melanoma cells to anti-Fas mAb-induced melanoma apoptosis (137); and siRNAs for the anti-apoptotic TRAIL-resistance factor cFLIP (138) have been shown to enhance melanoma apoptosis after treatment with either soluble TRAIL or Fas ligand through the increment of caspase-8 activity (139).