FADD and squamous cell carcinoma: Solamargine treatment up-regulated the expression of tumor necrosis factor receptors (TNF-R1 and TNF-R2) and the downstream signaling cascades of tumor necrosis factor receptor type 1-Associated Death Domain protein (TRADD) and Fas-Associated Death Domain protein (FADD), along with the activation of the mitochondrial pathway of apoptosis, in human hepatocellular carcinoma, lung cancer cells, breast cancer cells (SK-BR3, MCF-7, HBL-100 and ZR-75-1) [9], human squamous cell carcinoma SCCs [15], and human leukemia (K562) cell lines [16].