The mitochondrial pathway of apoptosis generally seems to be inhibited during infection, as demonstrated by the lack of caspase-9 processing, as well as the Bax translocation or release of cytochrome c. In infected cells, there is no upregulation of the pro-apoptotic BH3-only proteins Bad, Bid, Puma, Bim, and Bmf, but, in contrast to C. trachomatis, anti-apoptotic Bcl-2 and Mcl-1 are also not upregulated (Fig. 3). Here, MCL1 is linked to infection.