JAM2 and breast neoplasm: In another study, Costa et al. demonstrated that PDGFRβ highly expressed CAF-S1 subtype from four classified CAFs resected human breast tumor samples can attract and retain Treg cells through ligand for OX40 (OX40L), programmed cell death-ligand 2 (PD-L2), and junctional adhesion molecule 2 (JAM2), which contributed to an immunosuppressive microenvironment [37].