KCTD18 (potassium channel tetramerization domain containing 18) is a potassium channel-related gene located on chromosome 2 that appears to function as a regulator of cell proliferation. In a genome-wide association study of adipocyte biology, KCTD18 was identified as a regulator of fat cell proliferation through functional knockdown experiments in human adipose-derived stem cells, with genetic variants showing association with fat cell number at suggestive significance levels (P < 1.00 × 10-5) 1. The gene has been implicated in restless legs syndrome (RLS), where a shared haplotype spanning KCTD18 and SPATS2L was identified in three linked families with RLS4 locus on chromosome 2, with fine-mapping narrowing the candidate region to 46.9 Kb over KCTD18 2. KCTD18 missense mutations were significantly associated with glaucoma medication non-adherence in whole exome sequencing analysis (p < 10-3) 3. Additionally, KCTD18 was identified as a potential driver gene in primary signet ring cell carcinoma of the bladder 4. Duplication of KCTD18 in a 19.5 Mb chr2 region has been associated with neurological phenotypes including developmental delay, epilepsy, and autistic behavior, suggesting potential dosage sensitivity 5. These findings collectively indicate KCTD18 involvement in cell proliferation regulation and multiple disease pathways, though specific molecular mechanisms remain incompletely characterized.