Aires et al. (2020) reported that exosomes produced by retinal microglia under high intraocular pressure can propagate the inflammatory signals and promote retinal degeneration. Another two groups found that exosome derived from human placental MSCs and human 293T cells which express brain-derived neurotrophic factor (BDNF) can protect R28 cells (retinal precursor cells that represent RGCs) from hypoxia injury (Koh et al., 2020; Yan et al., 2020). Here, BDNF is linked to retinal degeneration.