However, several IHC markers, including tumour protein 63 (P63) and cytokeratins 5 and 6, commonly expressed in SCC, as well as thyroid transcription factor 1 (TTF-1) and cytokeratin 7 in ADC, have been proposed to differentiate between major NSCLC subtypes [10]. The gene discussed is TTF1; the disease is AIDS dementia complex.