An important point to consider is that our mouse model is not an RPE conditional knockout, meaning that adjacent photoreceptors also lacked Bbs8. We and others have already shown that loss of Bbs8 results in early onset retinal degeneration with significant photoreceptor outer segment disruption (Dilan et al., 2018; Kretschmer et al., 2019). Here, TTC8 is linked to retinal degeneration.