Human PPCD has been linked to three chromosomal loci, PPCD1 (OVOL2) on Chromosome 20 [5, 8–10], PPCD2 (COL8A2) on Chromosome 8 [11], and PPCD3 (ZEB1) on chromosome 10 [12]. This evidence concerns the gene ZEB1 and posterior polymorphous corneal dystrophy.