TF and neoplasm: Despite some TF overlaps in individual tumor samples, we were able to classify the tumors as SCLC-A (N = 90, 59.6%), SCLC-N (N = 14, 9.2%), SCLC-P (N = 36, 23.8%), and SCLC-Y (N = 10, 6.6%), except for one tumor (0.6%) that was quadruple-negative (SCLC-QN; Fig. 1a, b).