(A) CNGβ1 (green: antibody targeted CNGβ1 distal to the mutation site) was expressed in the outer segments of the treated regions of Cngb1–/– retinae 3, 9, and 23 months after treatment. The untreated region from the retinae 3 months after injection and the 28-month-old untreated Cngb1–/– retinae did not express full-length CNGβ1. (B) CNGα1 (green) was expressed and correctly targeted to the photoreceptor outer segments in the treated regions of Cngb1–/– retinae 3, 9, and 23 months after treatment, but was not detectable in the untreated region. Scale bar: 50 μm.