EGFR and cancer: Thus, through its off-target inhibition of EGFR in cancer cells or pericytes and ITK in T cells, ibrutinib can directly suppress the tumorigenicity and growth of EGFR-dependent solid tumors and dampen the pro-tumoral function of pericytes with EGFR mutations, while indirectly promoting anti-tumor TH1 and CD8 T cell responses to attenuate tumor progression.