It is important to note that the type of genetic defect in animal models (knockout/loss of function or missense mutations) and the genetic background strain with associated genetic modifiers impact the severity of the phenotype and the utility of the model for human disease, as was demonstrated in mouse models of Cep290-associated ciliopathies (Ramsbottom et al., 2015, 2020). The gene discussed is CEP290; the disease is ciliopathy.