In 1980, Ray White and colleagues published a landmark paper describing a strategy to produce a genetic map of the human genome utilizing evenly spaced DNA markers called restriction fragment length polymorphisms (RFLPs). These markers provided signposts along each chromosome that provided the critical framework upon which to map the locations of disease genes, Prominent examples included genes responsible for Huntington’s disease (chromosome 4, 1983), cystic fibrosis (chromosome 7, 1985) and BRCA1 (chromosome 17, 1990). For mapping purposes RFLPs were superseded by polymorphic STR (short tandem repeat) microsatellite markers in the early 1990s. Concurrently, physical maps of the human genome were produced using artificial chromosomes, cloning vehicles for large DNA inserts, first yeast and then bacterial. The physical map provided the reference framework for the sequencing effort of the public consortium.