ATP11A encodes a catalytic component of a P4-ATPase flippase complex that maintains plasma membrane phospholipid asymmetry by transporting phosphatidylserine (PS) and phosphatidylethanolamine (PE) from the outer to inner membrane leaflet 1. This flippase activity is essential for preventing inappropriate exposure of PS 'eat-me' signals on cell surfaces, which would otherwise trigger phagocytic clearance 23. ATP11A plays crucial roles in multiple developmental processes, including muscle cell morphogenesis where it mediates PS enrichment to trigger calcium signaling and myotube formation 4, and syncytiotrophoblast formation during placental development 4. The protein is highly expressed in auditory nerve fibers and cochlear neurons 1. Disease-causing variants in ATP11A lead to autosomal dominant auditory neuropathy type 2 (AUNA2), where deletions disrupting flippase activity cause progressive hearing loss 51. Additional pathogenic missense variants are associated with refractory focal epilepsy and hypomyelinating leukodystrophy, with phenotype severity correlating with variant location relative to transmembrane domains 6. Reduced ATP11A expression has also been implicated in critical COVID-19 outcomes, suggesting broader roles in immune regulation 7.