As a proto-oncogene, ATF3 expression is elevated in human breast cancer (Yin et al. 2008), malignant human prostate cancer (Pelzer et al. 2006), malignant Hodgkin's lymphoma (Janz et al. 2006), and squamous cell carcinoma (Wu et al. 2010). This evidence concerns the gene ATF3 and squamous cell carcinoma.