However, our screening results show that CDK4 and CDK6 are only essential in certain HNSCC cell lines, aligned with their limited efficacy in early clinical trials.38 By contrast, CDK1 and CDK7 were revealed as widespread essentialities across all HNSCC cell lines tested, thereby emerging as the best targetable candidates. The gene discussed is CDK4; the disease is head and neck squamous cell carcinoma.