TTF1 and adenocarcinoma: The research results show, besides diagnostic, prognostic significance as well; p63 is a favorable prognostic factor in patients with squamous cell carcinoma [4], overexpression of TTF-1 prolongs the overall survival of adenocarcinoma patients both in the early and advanced stages of the disease [5], while Multivariate analysis by Svarton M and associates defines these immunohistochemical markers as the only significant parameters for progression-free survival and overall survival rates in patients with NSCLC treated with erlotinib [6].