ALK and squamous cell carcinoma: Interestingly, a study described a 69-year-old never-smoking male NSCLC patient with EGFR/ALK wild-type adenocarcinoma, who developed sequential histological transformations—adenocarcinoma with sarcomatoid change, squamous cell carcinoma with sarcomatoid change, and pure squamous cell carcinoma—during chemotherapy, radiotherapy, and pembrolizumab treatment.