These data, together with our current study’s data, link the role of SEMA7A as increasing during postpartum involution, causing a normal increase in protumorigenic changes, including lymphatic channels in the remodeling breast, and also resulting in the overexpression of SEMA7A in developing breast cancers with increased propensity towards LVI and LN positivity at breast diagnosis in postpartum women. Here, SEMA7A is linked to breast cancer.