The relationship between the length of CSEPs, the degree of positive selection and the ratio of expression in haustoria compared to expression in epiphytic hyphae. Ratio of the non-synonymous to synonymous substitutions (Ka/Ks) within CSEP families is plotted against the length of the proteins. The values of the parameters for the axes were calculated as family averages; the family numbers are indicated in the circles. The ratios of CSEP expression in haustoria and epiphytic hyphae are as indicated in the colour bar. The diameter of the circles indicates the relative size of the families.