MC1R and melanoma: Furthermore, α-MSH/MC-1R signaling seems to be important for the induction of tumor-specific cytotoxic CD8+ T cells in vivo since in comparison to wt controls C57BL/6Je/e mice inoculated with similar numbers of B16 melanoma cells showed an increased tumor growth and reduced infiltration of CD8+ cytotoxic T cells in tumor-draining lymph nodes (Figure 4C).