PTGES and Fever: In the previously mentioned study using mice chimeric for mPGES-1, the terminal isomerase in which absence there is no fever in response to LPS (Engblom and others 2003; Eskilsson and others 2017; Nilsberth and others 2009b), Engström and others (2012) showed that mice with deletion of mPGES-1 in hematopoietic cells displayed a normal first phase of fever, whereas mice that expressed mPGES-1 only in hematopoietic cells showed no fever (but instead hypothermia) (Fig. 7).