S1PR1 and breast neoplasm: In summary, we hypothesize that pH-sensitive and tumor-targeted nanoparticles BAF312@cRGD-CaP-NPs could efficiently inhibit breast tumor growth and angiogenesis by downregulating the S1PR1/P-STAT3/VEGFA axis (Scheme 1), therefore achieving the goal of antitumor growth and inhibiting tumor angiogenesis for patients with BRCA or TNBC.