USF1 and breast carcinoma: While, in prostate cancer cells and breast cancer cell lines, it has been shown that loss of USF transcriptional activity is associated with carcinogenesis, in lung cancer it was demonstrated that USF‐2 represents an early marker for the development of bronchial dysplasia and non‐adenocarcinoma,38, 39, 40 thus suggesting a complex role for these transcription factors.