Since TGFβ upregulates genes responsible for the activation of the EMT program20, and because the miRNA signature is capable of stratifying between primary and metastatic lesions ex vivo6, we hypothesize that TGFβ supports differential expression of the signature miRNA between erlotinib-resistant and –sensitive NSCLC. The gene discussed is TGFB1; the disease is non-small cell lung carcinoma.