PSMD10 and infection: In further agreement with earlier reports showing increased expression of type IV secretion components and putative effectors of R. rickettsii in tick vectors during blood meal [8], we also observed up-regulation of transcripts encoding for VirB6, VirB8, and VirB9, ankyrin repeat proteins (Ank proteins), tetratricopeptide repeat proteins (TPR), acid phosphatase, and metalloprotease during tick cell infection (Additional file 2).