These include Arginase 1 (ARG1, linked to many human diseases), reticulons (linked to AD and amyotrophic lateral sclerosis) [59], proton myo-inositol cotransporter (SCL2A13, linked to AD) [60], Rab GDP dissociation inhibitor (linked to mental retardation) [61], and several tumor genes such as tumor protein D52 (TPD 52), tumor suppressor gene e-cadherin like, and protein phosphatase2A (PP2A); a few of these genes and their expressions in young, adult, and old L. stagnalis are shown in Additional Fig. 3. The gene discussed is ARG1; the disease is Alzheimer disease.