Fig. 4

Analysis of ALK fusion genes in 188 plasma samples of NSCLC patients by RT-qPCR and FISH. (a) ALK fusion genes are determined by 3′/5′ portion RT-qPCR of the ALK gene. The expression of ALK gene was calculated using 2^-△△CT method. (b-c) The representative FISH images for patients with ALK fusion gene (+) (b) and ALK fusion gene (−) (c). Red arrow, split red-green dots or single red dots are indicative of ALK rearrangement; yellow arrow, or touching red-green dots are indicative of no ALK rearrangement