TTF1 and squamous cell carcinoma: The histology revealed poorly differentiated squamous cell carcinoma with SMARCA4 deletion, and IHC indicated AE1/AE3 (+), cytokeratin 7 (CK7) (+), cytokeratin 5/6 (CK5/6) (focal +), p40 (partial +), TTF‐1 (−), napsin A (−), synaptophysin (Syn) (−), SMARCA4 (−), integrase interactor 1 (INI‐1) (+), Ki‐67 (90% +).