HIF1A and infection: During K. pneumoniae infection the spread of the pathogen is associated with siderophores as they down-regulate transcription factor HIF-1α responsible for mucosal immunity and cellular intrinsic immunity (Holt et al., 2015) the hypothesis that HIF-1α down-regulation increases the infection rate is usually common in Klebsiella infections (Holden et al., 2016).