circ_SEMA4B and the newly encoded protein SEMA4B-211aa were significantly down-regulated in BC tissues and exerted tumor suppressive effects in vivo and in vitro43 SEMA4B-211aa inhibits AKT (Thr308) phosphorylation by inhibiting PIP3 (phosphatidylinositol-3,4,5-trisphosphate) production through competition with p110 and binding to p85. The gene discussed is SEMA4B; the disease is breast cancer.