Here, we utilized patient-derived human induced pluripotent stem cell (hiPSC) retinal pigment epithelium (RPE) (hiPSC-RPE) cell lines associated with phenotypic manifestations of BD, ADVIRC, or ARB to investigate functional consequences of BEST1 mutations in an attempt to categorize the diverse types of mutations. This evidence concerns the gene BEST1 and Behcet disease.