EGFR and cancer: Furthermore, TGF-α expression was strongly correlated with EGFR inhibitor sensitivity and apoptosis induction upon EGFR inhibitor treatment in a panel of 42 NSCLC cell lines, only 2 of which carried EGFR mutations.43 Interestingly, while we anticipated that upregulated TGF-α in the cancer cells would act as a mitogenic growth factor via autocrine/juxtacrine signaling to Egfr expressed in those cancer cells, both genetic and pharmacological interference with this signaling axis caused an increase in the frequency of apoptosis, not a reduction in cancer cell proliferation.