Of note, the (R)-crizotinib effects apparently depend on the tumor microenvironment, because in vitro treatment of naïve CD4+ T cells in the presence of the TKI and suitable differentiation factors (Supplementary Fig. 13a) failed to affect the expression and secretion of major cytokines (IFNγ, IL-4, IL-9, IL-17) and Foxp3 by all major CD4+ T T cell subsets (Supplementary Fig. 13b–i). Here, CD4 is linked to neoplasm.