UBE2B and melanoma: Besides the role of RAD6 in TLS, we have demonstrated a relationship between RAD6B and canonical Wnt signaling in melanoma [15,16,17] and in breast cancers [18,19] wherein RAD6B stabilizes β-catenin via 26S proteasome-insensitive K63-linked polyubiquitination, and β-catenin in turn induces RAD6B transcription [18,19].