CTLA4 and melanoma: Interestingly, while the granzyme B degraded type IV collagen (C4G) fragments were increased in melanoma patients responding to anti-CTLA-4 treatment and modulated by inducing T cell activity in vivo, another MMP-degraded type IV collagen (C4M) fragment showed the opposite prognostic potential in the melanoma patients treated with anti-CTLA-4 and was not modulated by inducing T cell activity in vivo [73, 86].