XBP1 and infection: Interestingly, in response to infection, the first study speculates that the activation of PKR may be due to increased expression of PKR activating stimuli other than dsRNA (Pereira et al., 2010), while the later study found that XBP1 splicing also occurred following infection with L. amazonensis suggesting that the UPR pathway was activated along with PKR/PERK/P-eIF2α activation (Dias-Teixeira et al., 2017).