ALK and non-small cell lung carcinoma: However, a previous study showed that aberrant TGFβ signaling plays a crucial role in the acquisition of resistance to crizotinib in ALK-rearranged NSCLC cells in response to chronic, repeated exposure to crizotinib36, suggesting the presence of a latent association between TGFβ and ALK signaling with respect to a complex mechanism of cancer drug resistance.