PTPRC and melanoma: In coculture with the HLA-A*02:01–positive MART-1–expressing human melanoma cell line SK-MEL-5, the MART-1–specific CD8 T cells loaded with CD45-tethered IL-12 showed increased cytolysis of the target cancer cells without an apparent dose dependence for the levels of IL-12 loaded on the T cells (Fig. 3, A to C).