Relationship between consensus Kozak sequence at the true start ATG for genes affected by NMD compared with all genes. In each panel the x-axis corresponds to the sequence considered while the y-axis refers to the percent occurrence at each nucleotide position expressed as 'bits' using Weblogo . The top panel (in yellow) shows the consensus among all transcripts with an annotated 5' UTR and reveals the importance of an adenine in the -3 position - this is the classic Kozak consensus. This occurrence of adenine at the -3 position decreases significantly with increased NMD regulation as is shown in the bottom panel (red). The significance of change in enrichment of the adenine at -3 between NMD regulated and all genes was determined by chi-squared test. Pval, P-value.