XIAP is maintained at high levels in LVS-infected PMNs via increased expression of the BIRC4 gene and by upregulation of calpastatin (CAST), which prevents calpain-mediated XIAP degradation in healthy cells and during LVS infection (Luo and Loison, 2008; Schwartz et al., 2013; McCracken and Allen, 2014; McCracken et al., 2016). Here, CAST is linked to infection.