ENPP2 and head and neck squamous cell carcinoma: Specifically, we found 6 genes for HNSCC (AOX1, NMNAT2, ENPP3, NADK, CD38, and PARP1), 11 genes for LuSCC (AOX1, NNMT, NMNAT2, NMNAT3, ENPP2, ENPP3, NMRK2, NADSYN1, SIRT1, CD38, and PARP1) and 11 genes for CeSCC (AOX1, NMNAT3, ENPP1, ENPP2, ENPP3, NMRK2, PNP, NADSYN1, SIRT1, SIRT3, and CD38);