MAPK8 and breast carcinoma: Considering that ZEB1 potentially functions through the NF-кB, PI3K and MAPKs pathways in breast cancer [32–34], MDA-MB-231 cells were transiently transfected with the ZEB1 expression plasmid or empty vector control, followed by treatment with BAY (NF-кB inhibitor), PI-103 (PI3K inhibitor), PD98059 (ERK inhibitor), SB203580 (p38 inhibitor), or SP600125 (JNK inhibitor).