SP1 and breast cancer: Overexpression of FUT4 in the breast cancer cell lines MCF-7 and MDA-MB-231 is regulated by certain transcription factors (heat-shock factor 1 and Sp1) and micro-RNAs (miR-224-3p and miR-493-5p), all of which have a direct effect on breast cancer cell proliferation and invasion again through the PI3K/Akt and ERK/MAPK pathways (87).