LRRC41 (leucine-rich repeat containing 41), also known as MUF1, is a substrate recognition component of E3 ubiquitin ligase complexes that regulates protein degradation and cellular signaling. The protein contains a characteristic BC-box motif and can assemble with Elongin BC, Cullin family members (Cul2, Cul3, or Cul5), and Rbx1 to form functional E3 ubiquitin ligase complexes 1. LRRC41 functions as a predominantly nuclear dimeric protein that mediates ubiquitination of target substrates 2. In spermatogonial stem cells, the CRL2LRRC41 complex ubiquitinates DDX5 (ATP-dependent RNA helicase), promoting its interaction with the RNA-binding protein ELAVL1 without triggering proteasomal degradation, thereby enhancing Noggin transcript stability and supporting cell proliferation and migration 3. Pathologically, LRRC41 is overexpressed in hepatocellular carcinoma (HCC) and exhibits significant positive correlation with tumor recurrence, metastasis, and poor prognosis, making it a candidate therapeutic target 4. These findings reveal LRRC41's dual role in normal cellular homeostasis and cancer progression through ubiquitin-mediated protein interactions.