PITX3 and cataract: Three additional groups of individual and/or clustered loci include genes encoding DNA-binding transcription factors regulating lens development (Foxe3, Gata3, Hsf4, Maf, Prox1, Pitx3, Rarb, Sox2 and Tfap2a), proteins involved in lens morphogenesis and differentiation (Bfsp2, Bmp4, Bmp7, Cryba4-Crybb1, Cryba1, Cryba2 and Rb1), and novel cataract genes identified by recent human genome-wide association studies (GWAS), such as Casz1, Gstm2, Krtp2-Dpm3-Efna1 and Sema4d [80] as shown in Additional file 4, Figs. S12-20; file 5, Figs. S21-27; and file 6, Figs. S28-31; respectively.