LAT2 and presbycusis: Functional studies of human SLC7A8 variants (14:23597290A/T, 14:23598917G/A, 14:23608641C/T, 14:23598870G/A) found in age-related hearing loss (ARHL) patients showed decreased LAT2 transport activity, further supporting the causative link (Espino-Guarch et al., 2018).