TTF1 and squamous cell carcinoma: When combining IHC and molecular pathology, the following cascades have been demonstrated in pulmonary carcinomas: epidermoid carcinoma–epidermal growth factor receptor (EGFR) and HER-2 polysomy, and CK7/vimentin for EMT non-pure epidermoid carcinomas; bronchial-pulmonary adenocarcinomas -non-smoking female—mut EGFR and excision repair cross complement group 1 (ERCC1) expression; micropapillary pattern with VIM/RB/ERCC1 expression; acinar/BA—lepidic/micropappilary patterns express TTF1, and mutated EGFR.