With many known calcium-activated potassium channels expressed in RGCs (Wang et al., 1998) and amacrine cells (Grimes et al., 2009; Tanimoto et al., 2012), we speculate that PV-positive retinal neurons in the PV-Pten+/– mice could also have this channelopathy and a decrease in RGC intrinsic excitability. This evidence concerns the gene PTEN and channelopathy.