The function of CD4+ T cells was demonstrated in an MYC T cell acute lymphoblastic lymphoma (T-ALL) model where MYC inactivation correlated with an increase in expression of the cytokine Thrombospondin-1 (TSP-1), leading to induction of senescence and inhibition of angiogenesis by intra-tumoral CD4+ T cells [63]. Here, MYC is linked to acute lymphoblastic leukemia.