From a global perspective, two external developments are having dramatic effects upon the field of statistical genetics: improved genetic data, for example, human DNA sequence, and new technologies, for example, microarray technology. Meiotic mapping techniques will have to be adapted to benefit from the improved data, for example, allelic association studies have to be extended to multiple markers to profit from the new genetic map of SNP markers. Changing technology has led to ever-increasing knowledge about gene function which has enabled novel gene mapping strategies which we refer to as functional mapping. Functional mapping has great potential for mapping complex disease genes since it uses pathway fractions to intermediate between genotype and phenotype information. Methods used in whole-genome gene expression studies are used to illustrate concepts of functional mapping.