LPA and colitis: Furthermore, in a rat dextran sulphate sodium (DSS) colitis model, rectal instillation of recombinant NPP7 was shown to alleviate colitis activity (10), and in a murine DSS colitis model NPP7 knockout (KO) mice were shown to have more severe colitis activity with increased levels of PAF, LPA, and autotaxin (8).