NTRK1 and small cell lung carcinoma: In a very recent study, Leal et al. used a cocktail of pan-TRK (clone A7H6R, Cell Signaling), ALK, and ROS-1 antibodies on TMA and found a positive reaction in 0.4% of NSCLC (2/522), while all SCLC (105) were negative for this antibody cocktail.