Linear organization of gene clusters centering upon the chromosomal loci of the FGFR genes in humans. Paralogous genes present in at least two of the four loci are shown, with the exception of the region between GPX3 and NKX2E on chromosome 5, which appears to represent a series of intervening genes inserted after duplication of the 4p16/5q32-35 clusters, and genes mentioned in Fig. 3. Corresponding syntenic mouse chromosomal regions (mm*) are indicated. Takifugu rubripes scaffolds are shown (TR*) that contain more than one homologous gene from these clusters. Further details on the location of paralogous genes can be found in [see Additional file 1].