The pathological mechanism that involve semaphorins in ROP is initiated when the resting microglia cells become activated in the ischemic areas of the retina and trigger the secretion of pro-inflammatory cytokines, particularly IL-1 that stimulate the production of pro-apoptotic/repulsive factor Semaphorin3A (Sema3A) specifically in retinal ganglion neurons [44, 120]. This evidence concerns the gene SEMA3A and retinopathy of prematurity.