In this regard, polymorphisms on several immune-related genes have been associated with susceptibility to infections including pattern recognition receptors (prr) and downstream signaling molecules (Skevaki et al., 2015), mannose- binding lectin 2 (mbl2) and toll-interleukin 1 receptor domain containing adaptor protein (tirap) (Gowin et al., 2018), c-c chemokine receptor type 5 (ccr5) (Martin et al., 1998; Salkowitz et al., 2003; Fellay et al., 2009; Chapman and Hill, 2012), interleukin 6 (il-6) (Zhang et al., 2012), and il-22 (Zhang et al., 2011), among others. Here, CCR5 is linked to infection.