Western blot of RBL-1 cells transfected with ELANE vectors containing translational start-site mutations, using an antibody to the carboxyl terminus of NE. Mutations of the canonical methionine initiation codon (c.3G>A and c.1A>G) and the noncoding Kozak sequence (c.-3A>T) lead to expression of shorter isoforms of ELANE. When the upstream region is removed and only the ORF that corresponds to each ATG codon is expressed, separated isoforms are identifiable (ATG2 ORF, ATG3 ORF, and ATG 4 ORF). Molecular weight markers (in kDa; right) and NE isoforms (arrows; left) are shown.