Furthermore, the addition of EGF significantly increased EGFR phosphorylation in A549, Hela, and A431 cells (Supplementary Fig. 17), but had no significant effects on EGFR mutant cells (e.g., HCC827, PC-9, and H1975) (Fig. 3h and Supplementary Fig. 16), implicating high baseline of EGFR activation in cancer cells carrying EGFR-activating mutations. Here, EGF is linked to cancer.