ELOC (elongin C, formerly TCEB1) is a core component of cullin-RING E3 ubiquitin ligase complexes (CUL2/CUL5-RING) involved in protein ubiquitination and degradation. In cancer biology, ELOC functions as part of the VHL-containing E3 ligase complex that regulates HIF1A stability; mutations affecting the VHL-binding domain of ELOC disrupt this interaction, leading to HIF1A accumulation 1. ELOC mutations were formally recognized as defining a distinct renal cell carcinoma subtype in the 2022 WHO classification 234. ELOC-mutated RCC is characterized by biallelic ELOC inactivation without VHL mutations, representing a molecularly defined tumor entity with distinctive genomic features 5. Clinical significance: ELOC-RCC patients demonstrate superior overall and progression-free survival compared to stage- and grade-matched VHL-deficient clear cell RCC, with simpler karyotypes, fewer somatic copy number alterations, and generally indolent behavior 5. Pathogenic ELOC variants contribute to hereditary renal cancer predisposition 6. Beyond renal cancer, ELOC participates in ubiquitin-dependent protein degradation pathways involving HIF1A regulation in colorectal cancer stemness and chemoresistance 7.