However, more and more studies from other research groups have shown that a good response to crizotinib therapy was observed in some patients with NSCLC in which the percentage of ALK rearrangement positive cells was <15%, indicating the existence of low levels of ALK rearrangement and a focal, non-random distribution of positive cells in some NSCLC cases [24,25,26,27,28]. The gene discussed is ALK; the disease is non-small cell lung carcinoma.