NDP and Norrie disease: Accordingly, while literature suggest the existence of digenic involvement of RS1 and NDP in the pathophysiology of retinoschisis and Norrie disease, ours is a preliminary study wherein, apart from in vitro experiments using human retinal samples, we have used in silico approaches using open access protein–protein interaction databases that provide information derived from multiple sources like experimental findings, computational predictions, mining of other databases and literature [35], to determine the association between the two proteins of interest, RS1 and NDP.