RACK1 and breast carcinoma: Previously, p-glycoprotein (P-gp) was shown to bind ANXA2 and promote multidrug-resistant breast cancer invasion by regulating the phosphorylation of ANXA2, and further studies revealed that P-gp-mediated phosphorylation of ANXA2 is regulated by the receptor for activated C kinase 1 (RACK1) [36].