Thus, in breast cancer cells, the C-octyl nojirimycin-related derivative 5 (Figure 1) promoted a reduction in the phosphorylation levels of focal adhesion kinase (FAK) and extracellular signal-regulated kinase 1/2 (ERK1/2) [48], a member of the mitogen-activated protein kinase (MAPK) group. This evidence concerns the gene MAPK3 and breast cancer.