RAB28 and Rod-cone dystrophy: The association of RAB28 and BBSome gene disruption with cone-rod dystrophy (Roosing et al., 2013; Riveiro-Álvarez et al., 2015; Lee et al., 2017; Ying et al., 2018) and retinitis pigmentosa (Waters and Beales, 2011; Weihbrecht, 2017) raises the possibility that EV regulatory functions contribute to human retinal disease.