Hope an easy one.
I have a genotyped data (Illumina Inﬁnium HumanHap550) and was told it is Build 21. I need to LiftOver it to the latest build GRCh37/hg19. Found this website http://genome-archive.cse.ucsc.edu/downloads.html#human to get LiftOver "chain files". Can you tell me which hg corresponds to Build 21? Any advice on LiftOver would be useful, too.