highly significantP = 5.7 × 10 −20
We found a highly significant and large effect of the nucleotides at position −3 and at position −2 on translation efficiency (Bonferroni adjusted Kruskal–Wallis test P = 5.7 × 10 −20 for position −3; P = 1.2 × 10 −17 at position −2) ( Fig. 5 A; Supplemental Fig.