CDK7 and head and neck squamous cell carcinoma: Additionally, CDK7 knockout (KO) and selective inhibitors (YKL-5-124 and samuraciclib) demonstrated potent antitumor activity, effectively suppressing tumor growth in HNSCC patient-derived organoids (PDOs), as well as in both cell line- and patient-derived xenograft (PDX) mouse models with minimal toxicity.