To demonstrate that OHPg/PR-B could negatively regulate breast cancer cell migration (Figure 6A and Figure S4) and invasion (Figure 6B) through the phosphorylation status of Ser83 in Pxn, we carried out functional assays with single phosphomimetic S83E (serine to glutamic acid) Pxn mutants. The gene discussed is RB1; the disease is breast carcinoma.