Blood samples from these individual mice have also been analyzed by tandem mass spectrometry, examining a set of lysophosphatidylcholine derivatives (LPCs). The detailed findings for mice from the 11 week studies have been recently described [38]. Interestingly, the 18:0 LPC parallels the cholesterol ester/obesity response, whereas the other major LPC, 16:0, is unaffected by these conditions.