IRES activity from fragments of ELANE mRNA. (A) Activity from 3 overlapping regions of ELANE mRNA. Only region 1 showed an increase in IRES activity. Region 1: nt 171-233; Region 2: nt 42-233; and Region 3: nt 1-233 (NM_001972.2). (B) Activity from 3 tandem repeats of nt 171-193 of ELANE, either wild-type or mutant sequence. Data shown are mean ± standard deviation of 3 independent experiments. *P < .05 vs PRF; ^†P < .05 vs WT. WT, wild-type.