Second- and third-generation TKIs (i.e., afatinib and osimertinib) are currently approved for use in metastatic EGFR T790M mutant-positive NSCLC [28,29]; however, these two medicines unavoidably cause severe on-target side effects [30] and acquired resistance mutations in EGFR exon 20 C797S [31] and G796D [32]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.