Plasma cells (PCs) in the spleen utilize CXCR4 to position in the red pulp, and those in the LN use CXCR4 to position in the medulla. PCs egress into circulation using S1PR1 (blue cells), while a subset remains resident in spleen and LNs (green cells). Depending on the type of immune response, different subsets of PCs develop. These subsets express distinct chemokine receptors that govern their tissue tropism, with CXCR4hi PCs predominantly homing to BM sinusoids, CXCR3+ PCs homing to inflamed tissue, and CCR9 / CCR10+ PCs from Peyer’s or cecal patches homing to gut tissues.