FOSL1 and esophageal squamous cell carcinoma: Moreover, Fra-1 has been implicated in cervical cancer stem cell radio-resistance (14), in the malignant progression of esophageal squamous cell carcinoma through MAPK/MEK/ERK/FRA-1 pathway activation (15), in epithelial-mesenchymal transition regulation of colorectal cancer cells (16, 17), in cancer stem cell formation from non-stem cells in a PKCα-dependent activation of Fra-1 (18), and in the inhibition of p53-dependent apoptosis in lung cancer (19).