With the KID functions of EGFR on board, a hypothesis pertaining to EGFR's divergent roles in regulating growth vs. survival of cancer cells in relevant to TKI resistance is proposed as the following (Figure 3): EGFR exists in two types of status, one is kinase activatable and the other is kinase unactivatable (functions as a scaffold protein), the former is mainly in charge of cell growth, the latter is mainly in charge of survival. Here, EGFR is linked to cancer.