MAPK9 and breast cancer: In addition, when we depleted JNK2 in the two human breast cancer cells MDA-MB-231, which showed absent/very low expression level of p-JNKs and in MDA-MB-453, which expressed both JNK2 and p-JNKs, distinct loss or gain of FRA1- expression were also observed in these two cell lines (Supplementary Figure 1G).