JUNB and breast carcinoma: These observations consequently pointed to a crucial role for JUNB in promoting the progression from G1 to S. Both the decrease in the fraction of cells in S and the G0/G1 arrest were also observed in epithelial cell lines derived from a uterine cervix carcinoma (HeLa), a lung adenocarcinoma (H1395), and a breast cancer (MCF-7) (Additional file 1: Fig. S1B and S1C).