NKAIN2 (sodium/potassium transporting ATPase interacting 2) is a gene located on chromosome 6 that regulates sodium ion transport through interaction with Na+/K+-ATPase enzymes 1. The gene exhibits multiple functional roles across different biological contexts. In neuropsychiatric disorders, NKAIN2 shows sex-dependent genetic effects on schizophrenia, bipolar disorder, and major depressive disorder risk, implicating neuronal excitability mechanisms 1. A genome-wide association study identified NKAIN2 as a modifier gene associated with negative symptoms in schizophrenia 2, and NKAIN2 emerged as a top contributor to ADHD pharmacological treatment response prediction 3. NKAIN2 functions as a putative tumor suppressor gene located within the commonly deleted 6q region. In prostate cancer, NKAIN2 overexpression inhibits cellular growth, promotes apoptosis, and suppresses migration and invasion, while knockdown produces opposing effects 4. In pancreatic cancer, NKAIN2 is directly targeted by miR-181d, and its downregulation suppresses cancer development 5. Neuroblastoma studies revealed high NKAIN2 expression in aggressive tumors and MYCN-amplified cell lines, with downregulation during differentiation 6. Additionally, NKAIN2 shows positive selection signals in Tibetan pigs, suggesting roles in cardiorespiratory adaptation to high-altitude hypoxia 7.