UASt regulatory sequences drive expression of a 3.3kb Mmus\Numb cDNA. Xenopus β-globin 5' UTR sequences sequence encoding a Tag:MYC epitope are added at the N-terminal end of the cDNA sequence. The encoded protein is predicted to have an additional 44 amino acid residues, MEEKLISEEDLEDGTRVKLRNLSKVTQLVKGTAKIQSQVVKVN, at the N-terminal end.