ANXA5 and infection: In vitro-derived MPs were predominantly (>80%) TER119+, and although a proportion of the in vitro-derived MPs (<20%) expressed Annexin V+, the levels of Annexin V expression were substantially lower (MFI of 40.0 for in vitro-derived MPs vs MFI of 98.5 for infection-derived MPs) than for infection-derived MPs (Fig. 4B).