TSPAN18 and cutaneous melanoma: Pan-cancer analysis revealed that the vast majority of TSPAN family members were differentially expressed in multiple tumor types, including prostate adenocarcinoma, rectal adenocarcinoma, skin cutaneous melanoma, testicular germ cell tumors, cholangio carcinoma, colon adenocarcinoma, lower-grade brain glioma, pancreatic adenocarcinoma and GBM (see Additional Files 1).