KIAA1755 is a gene with guanyl-nucleotide exchange factor activity that localizes to the cytoplasm and plasma membrane, playing roles in axon guidance and cardiac rhythm regulation. The gene has been identified as a candidate for heart rate variability (HRV), with genome-wide association studies revealing that KIAA1755 variants are significantly associated with HRV traits 1. Functional validation in zebrafish demonstrated that disruption of the KIAA1755 orthologue (si:dkey-65j6.2) influences HRV, confirming its role in cardiac rhythm regulation 2. KIAA1755 also shows disease relevance across multiple conditions. In chr20 lymphocytic leukemia, the long non-coding RNA lnc-KIAA1755-4 is overexpressed and serves as a poor prognostic marker, with high expression associated with adverse clinical characteristics and shorter overall survival 34. In breast cancer, a coding variant (rs1205434) in KIAA1755 is associated with increased disease risk, particularly showing interaction with age at menarche 5. The gene has also been identified as a hub gene in intracranial aneurysm networks and as a potential target for prostate cancer-related microRNAs 67. Clinically, KIAA1755 represents a potential biomarker and therapeutic target across cardiovascular and oncological conditions.