The expression of differentiation antigens that are commonly present and have been previously used as immunological targets in melanoma, namely, TYR (tyrosinase) and MLANA (Melan-A/MART1) [20,33], were compared with CTAG1A and ROPN1 or ROPN1B in our panel of melanoma cell lines. Here, CTAG1A is linked to melanoma.