RNF11 (ring finger protein 11) is a 154 amino acid RING-H2 finger protein that functions as a multifunctional modulator of protein ubiquitination and cellular signaling pathways 1. The protein contains several functional domains including a RING-H2 finger domain, PY motif, ubiquitin interacting motif (UIM), 14-3-3 binding sequence, and AKT phosphorylation site 1. RNF11 regulates protein degradation by interacting with HECT-type E3 ubiquitin ligases including ITCH, SMURF1/2, NEDD4, and WWP1/2, positioning it as a master regulator of multiple signaling pathways 2. The protein modulates TGF-β signaling through direct association with Smad4 and can antagonize Smurf2-mediated inhibition 1. RNF11 also participates in ESCRT-dependent lysosomal degradation of receptors, particularly EGFR, where perturbation of RNF11 levels delays receptor degradation and sustains ERK1/2 phosphorylation 3. In neurological contexts, RNF11 specifically modulates dopamine neurotransmission, with knockdown increasing dopamine release and affecting dopamine transporter expression 4. RNF11 is overexpressed in several cancers and may serve as a diagnostic biomarker for certain conditions like fibromyalgia 25. The protein's high evolutionary conservation suggests a non-redundant cellular function 1.