PCLAF and myeloid sarcoma: In particular, a number of studies have demonstrated that platelets are present along with an increased activation status in the peripheral blood and in plaques of MS patients as indicated by elevated PMP levels, P-selectin expression (also known as CD62P), increased levels of platelet-activating factor (PAF) and upregulation of GpIIb receptor (see Figure 1) [30,33,34,35,36].