ALK and non-small cell lung carcinoma: Recently, an L1198F mutation in ALK was reported in an ALK rearranged NSCLC patient who first developed a crizotinib resistance mutation (ALK-C1156Y) and thereafter developed a second mutation ALK-C1156Y/L1198F, upon treatment with the third generation ALK tyrosine kinase inhibitor (TKI) lorlatinib, which results in a mutated ATP binding site that is once again crizotinib sensitive [24].