MERTK and retinal degeneration: Subsequently, the Mertk-/- mouse line became the fountainhead for the description of Mertk function in a spectrum of phenotypes spanning retinal degeneration, defective adult neurogenesis, neurodegenerative diseases, liver injury, lupus-like autoimmunity, and cancer (Cohen et al., 2002; Cook et al., 2013; Crittenden et al., 2016; Davra et al., 2021; Duncan et al., 2003a; Fourgeaud et al., 2016; Huang et al., 2021; Ji et al., 2013; Lindsay et al., 2021; Stanford et al., 2014; Tormoen et al., 2020; Zagórska et al., 2020).