ALK and small cell lung carcinoma: We used public databases to analyze the expression of ALK in pan-cancer and its prognostic value and analyzed the correlation between ALK and SCLC prognosis-related genes.<h4>Results</h4>A total of 685 patients diagnosed with SCLC underwent ALK testing, and 59 patients were identified to have abnormal expression of the ALK protein, with 10 cases showing strong expression, 14 cases displaying moderate expression, and 35 cases exhibiting weak expression.