ROS1 and cancer: Remarkably, two drugs targeting KGF-activated NTRK kinases, namely entrectinib (Rozlytrek, Roche), also approved for the treatment of ROS1-positive patients with metastatic non-small cell lung cancer (NSCLC)10,11, and larotrectinib (Vitrakvi, Bayer12), got accelerated FDA approval as the first tissue-agnostic drugs for the treatment of tumors testing positive for NTRK kinase fusions, regardless of the cancer type, shedding further light on the importance of KGFs as cancer targets.