PDCD1 and hypothyroidism: Existing literature suggests that previous treatment with TKIs appears to be a significant risk factor for developing hypothyroidism during PD-1 inhibitors therapy,[59] whereas no such association was found with previous chemotherapy.[60] Notably, our current hypothesis cautiously attributes the observed thyroid dysfunction primarily to sintilimab in this case, though future large-scale prospective studies are warranted to validate this causal relationship.