Similar to FBXL21 ubiquitinating MYOZ1 and TCAP, another E3 ligase, the FANCL subunit of the FA (Fanconi anemia) core complex, has been shown to monoubiquitinate two interacting proteins, namely FANCD2 and FANCI [48, 49]. This evidence concerns the gene FBXL21P and Fanconi anemia.