Reversible EGFR-TKIs like gefitinib and erlotinib have already been used for the treatment of lung cancer, but a comparative, controlled, and randomized trial of afatinib and gefitinib found that afatinib is more effective than gefitinib in treating NSCLC patients because it results in a greater duration of PFS (median 11.0 months versus median 10.9 months, HR: 0.73, p=0.017) and a longer time to treatment failure (median 13.7 months versus median 11.5 months, HR: 0.73, p=0.0073) [6]. Here, EGFR is linked to lung cancer.