CpG distribution in DRB1-e2, based on the dataset including the 374 complete DRB1-e2 sequences. A, each individual sequence lined under each other in the consensus numbering order starting from DRB1*010101. Black boxes indicate CpG dinucleotides and gray boxes other dinucleotides. B, CpG frequency for each nucleotide position. The dotted line indicates 100%.