In mcd/mcd mice, a transgenic mouse line (mcd/mcd) expressing a mutated form of cathepsin D that is enzymatically inactive and thus impairs the processing of phagocytosed POS in the RPE cells, TEM has revealed the presence of basal laminar and linear deposits, which are considered to be the hallmarks of AMD, similar to those observed in the 5XFAD mice [20]. The gene discussed is CTSD; the disease is age-related macular degeneration.