Analysis of phosphorylation of ERK1/2 showed that, although the kinetics were not similar, ERK1/2 activity was consistently increased by rIL-17B in the three breast cancer cell lines BT20, MDA-MB-468 and MCF7, (Figure 4B), but not in the IL-17RB deficient MDA-MB-435S cell line (Supplementary Figure 3D). This evidence concerns the gene IL17RB and breast cancer.