KRT7 and neoplasm: Tumor sections were immunostained with ready-to-use primary antibodies against cytokeratin 7 (CK7, Catalog Number: MAB-0828), TTF-1 (thyroid transcription factor-1, Catalog Number: MAB-0677), napsin A (Catalog Number: MAB-0704), CK5/6 (Catalog Number: RMA-1144), P40 (Catalog Number: RMA-1006), and Ki-67 (Catalog Number: MAB-0672, all were from Maixin Biotech Co., Ltd., Fuzhou, China).