Pitx3 is expressed in the lens vesicle and is later limited to lens epithelium (Shi et al., 2006; Ho et al., 2009), and Pitx3 deletion causes apoptosis, abnormal lens fiber differentiation, and loss of the lens (aphakia) (Semina et al., 1997; Rieger et al., 2001; Wada et al., 2014). This evidence concerns the gene PITX3 and congenital primary aphakia.