Microphthalmia-associated transcription factor (MITF) is a member of the basic/helix-loop-helix/leucine zipper (b-HLH-ZIP) transcription factor subfamily. MITF regulates the differentiation of melanocytes, optic cup-derived retinal pigment epithelium (RPE), and some types of bone marrow-derived cells. MITF is crucial for normal retina and RPE development. This lentivirus expresses one of the isoform of MITF, human MITF-D, under the control of the Tet promoter.