As shown in Fig. 5, dark-adapted ERG with a relatively high intensity stimulation (− 0.15 log sc td s) demonstrated essentially similar amplitudes of a- and b-waves in WT and Aqp9 KO mice with and without ONC, and with and without 4-CIN, indicating no functional abnormality of photoreceptor and second-order neurons among these mouse groups (n = 6, p > 0.17 for a-wave amplitude, p > 0.10 for b-wave amplitude, ANOVA). The gene discussed is AQP9; the disease is cervical squamous intraepithelial neoplasia.