At 12 months-of-age, reversal learning deficits were observed in CLN2R208X/R208X females during t-maze testing13, similar to that observed in other Batten disease large animal models (TPP1−/− dog and CLN5 sheep models)30–32, as animals approached end-stage, reversal deficits increased. The gene discussed is CLN5; the disease is juvenile neuronal ceroid lipofuscinosis.