ADD1 and lymphopenia: We defined coevolutionary clusters that were unique to each disease strain and among these clusters of genes identified two genes, Add1 and Gimap5, previously shown by positional cloning to underlie susceptibility to hypertension in MHS and lymphopenia and diabetes in BBDP, respectively (Bianchi et al., 2005; Ferrandi et al., 2010; Hornum et al., 2002; MacMurray et al., 2002).