It has been reported that lamp1-deficient mice are fertile and viable (Andrejewski et al., 1999), but lamp2 deficiency in mammals, such as in the mice or humans, leads to postnatal mortality (Tanaka et al., 2000), Danon disease (Nadeau et al., 2008), fatal cardiomyopathy and myopathy (Tanaka et al., 2000; Stypmann et al., 2006) due to a massive accumulation of autophagic vacuoles in many tissues, including skeletal muscle, liver, spleen and kidney (Tanaka et al., 2000). The gene discussed is LAMP2; the disease is cardiomyopathy.