A previous report suggested that soluble GARP is involved in the polarization of M2 macrophages, which is consistent with the findings in this study showing the cell-surface-bound GARP in mediating the reprogramming of macrophages to acquire the M2 phenotypes in the neoplasms.34 Nevertheless, the reprogramming of macrophages by PDA tumor cells via a cell-to-cell direct contact would unlikely involve soluble GARP. Here, LRRC32 is linked to Patent ductus arteriosus.