VDAC1 and infection: Of remaining ORFs, ~60 ORFs of the HF strain are likely required for macrophage infection, as orthologs of E. chaffeensis are essential for infection of macrophages including type IV secretion system apparatus (23 ORFs) and effector proteins (3), two-component regulatory system (6), and outer membrane proteins (porin, lipoproteins, invasin; ~30 ORFs) etc. (Kumagai et al., 2006, 2008; Huang et al., 2008; Mohan Kumar et al., 2013; Rikihisa, 2015, 2017; Lin et al., 2016; Sharma et al., 2017; Teymournejad et al., 2017; Yan et al., 2018).