ITPKC encodes inositol-1,4,5-trisphosphate 3-kinase C, an enzyme that phosphorylates inositol 1,4,5-trisphosphate (InsP3) to inositol 1,3,4,5-tetrakisphosphate, thereby regulating intracellular calcium homeostasis. The protein exhibits dynamic nuclear-cytoplasmic shuttling and is subject to calcium/calmodulin-dependent inhibition. Unlike the other two isoforms, ITPKC localizes predominantly to the cytoplasm and nucleus rather than the cytoskeleton or endoplasmic reticulum 1. ITPKC has garnered significant clinical interest in Kawasaki disease, an acute systemic vasculitis in children. A meta-analysis of over 3,800 cases revealed that the C allele of the rs28493229 polymorphism confers increased Kawasaki disease susceptibility (odds ratio 1.53, 95% CI 1.34–1.74), with associations detected across populations including Taiwanese, Korean, and North Indian cohorts, though effect sizes vary by ethnicity 2. Recent evidence suggests ITPKC participates in tumor microenvironmental regulation; in ovarian cancer, extracellular vesicles delivering ITPKC elevate nuclear IP4 levels and enhance homologous recombination repair, promoting chemoresistance that can be reversed using fluoxetine, an SSRI antidepressant 3. ITPKC polymorphisms have also been associated with cervical squamous cell carcinoma risk in Taiwanese women, likely reflecting its role as a negative regulator of T-cell activation 4.