ALK and non-small cell lung carcinoma: The randomized trial administered crizotinib to ALK-positive chemotherapy-naïve NSCLC patients, leading to extended PFS results (median 10.9 months versus 7 months; HR 0.45, 95% CI 0.35–0.60, ORR 74 percent versus 45 percent) and prolonged overall response rates at a median follow-up duration of 17 months when compared to chemotherapy-based therapy [20,21]; however, the availability of other mentioned TKIs renders crizotinib less desirable for first-line use because of its inferior PFS and CNS penetration.