I am running an experiment in which I need to compare the similarity of HLA alleles. To do this, I was thinking of looking for a phylogenetic tree of the HLA alleles. However, the only references I was able to find are from 1999: https://academic.oup.com/mbe/article/16/2/147/1018331/Locus-specificity-of-polymorphic-alleles-and, http://www.nature.com/gene/journal/v1/n2/abs/6363648a.html. A lot more HLA alleles have been classified and discovered since then, and I was wondering if anyone knew of a more recent resource. Thanks.