HLA-C and melanoma: Furthermore, the Giacomini group [33] carried out a detailed investigation by isoelectric focusing to distinguish HCs of HLA-C in complex mixtures of immunoprecipitated HLA-I molecules of two melanoma cell lines (SK Mel 37 and Colo 38) and two carcinoma cell lines (colon HT-29 and bladder T24) genotyped HLA-A, HLA-B, and HLA-C.