TYR and microphthalmia: Microphthalmia-associated transcription factor acts in part via direct transcriptional activation of genes (tyrosinase, TYRP1 and TYRP2) required for pigment synthesis (Bentley et al, 1994; Hemesath et al, 1994; Yavuzer et al, 1995; Yasumoto et al, 1997) and also has a role in melanocyte survival and differentiation (Lerner et al, 1986; Opdecamp et al, 1997; Hemesath et al, 1998).