RB1 and infection: This cycle can be divided into five steps: (i) the EB infects the host cell, mainly epithelial cells, via host receptors such as the protein disulfide isomerase (PDI), or the ephrin receptor A2 (EPHA2) [14]; (ii) within 2 h post infection (hpi), it differentiates in an “initial body” into an RB; (iii) thereafter, the RB divides by binary fission in an “inclusion” [14]; (iv) at ~18 hpi, the RB associates with the inclusion membrane and re-differentiates into EBs; (v) by 40–48 hpi, these EBs are released from the host cells by lysis or extrusion to start another round of infection [4].