These E3 ligases are known as Cullin-RING ubiquitin ligases (CRL4s) and they can ubiquitinate a great number of proteins involved in DNA damage and repair [e.g., DDB2 and UNG2 (Uracil-N-glycosylase 2)] 20-23, cell cycle progression (e.g., p21 and p27) 24, 25, and tumor suppression (e.g., PTEN and ST7] 26, 27. Here, PTEN is linked to neoplasm.