In a retrospective analysis of ROS1‐ and ALK‐rearranged NSCLCs treated with crizotinib in a phase 1 trial, we compared progression‐free survival (PFS) and objective response rate (ORR) based on the history of anticoagulation use (a possible surrogate of thromboembolism) at baseline (within 90 days before study enrollment) or within 90 days of study treatment. Here, ALK is linked to Thromboembolism.