*15.2. PI3NM3*

The phosphatidyl inositol transfer protein PIT3NM3 (aka CCL118) is the mammalian homologue of the *Drosophila* retinal degeneration gene, *rdgB*, and defects in it are associated with autosomal dominant cone-rod dystrophy CORD5 [154–159]. The protein has also been implicated in cancer metastasis [160]. In zebrafish, the Class I phosphatidylinositol transfer protein β isoform, Pitpnb, is essential for biogenesis and maintenance of double cones [161].
