SphK1 is overexpressed in head and neck SCC, and positively correlates with invasion and reduced sensitivity to radiotherapy.3–5 We have demonstrated that safingol induces apoptosis and autophagy in head and neck SCC cells.26–28 Recent studies reported anti-proliferative and cytotoxic effects of PF-543 on a panel of established and primary human colorectal cancer cells.19 Based on these findings, we decided to investigate the possibility that PF-543 induced cell death and autophagy in head and neck SCC cells. This evidence concerns the gene SPHK1 and colorectal cancer.