MITF and microphthalmia: Microphthalmia black-eyed-white mutant mice (Mitfmi-bw), which possess a spontaneous Mitf mutation involving the insertion of an L1 element into an intron [18] which abolishes the expression of the Mitf-M isoform, have a white coat but black eyes because they lack melanocytes while the RPE is normally pigmented and developed (Table 1).