SEMA3A and Alzheimer disease: As both semaphorins (Sema3a and Sema4c) are known to regulate nervous system development and plasticity (Carulli et al., 2021), it is possible that the murine version of Ramp3 to Sema3a interaction noted with AD pathology in humans (Wang et al., 2021) more precisely involves Sema4c (and not Sema3a) instead.