Independently of the resistance mechanisms, all osimertinib-resistant NSCLC cell clones maintained a higher phosphorylation of Rb in the presence of osimertinib when compared with the parental sensitive cell lines (Figure 1B); p-EGFR was inhibited in all cells with an EGFR-independent mechanism of resistance; only in PC9T790MC797S cells, carrying the triple mutated EGFR, osimertinib failed to inhibit phosphorylation. The gene discussed is RB1; the disease is non-small cell lung carcinoma.