Positive selection detection result of Kunitz/BPTI family in Ixodes scapularis. (A), Column charts of the posterior mean ω for each site in group I, group II and group III. In these charts, the blue, green and red columns are based on M3, M2a and M8, respectively. Positively selected sites are detected in both group II and group III, but not in group I. (B), Surface models of representative proteins in group I, group II and group III. Protein XP_002406145.1, AAM93612.1 and AAK97828.1 from group I, group II and group III, respectively, were modeled using the I-TASSER server. Positively selected sites with posterior probability > 95% (Table S4-S5) are located in the surface models (shown as stick with red color).