A downstream AUG translation start codon is selected for this CCDS representation based on a strong community standard for its use, and on a higher probability of a signal peptide being present in the protein N-terminus. The use of an alternative upstream AUG start codon would result in a protein that is 19 aa longer at the N-terminus. The upstream AUG has a weak Kozak signal while the downstream AUG has a strong Kozak signal. Due to leaky scanning by ribosomes, it is possible that some ribosomes may initiate translation from the downstream AUG codon while others start from the upstream AUG. The presence of multiple upstream ORFs suggests that a combination of leaky scanning and translational reinitiation may be necessary to achieve translation of the annotated ORF.