Myeloid cells originate in the bone marrow during hematopoiesis and encompass all hemopoietic cells except the lymphoid cells (T cells, B cells, NK cells and dendritic cells). Vascular endothelial cells can differentiate from common myeloid progenitors, and these cells that form the bone marrow-derived myeloid lineage express markers such as CD31, von Willebrand factor and Tie2. Other myeloid markers may be used to track certain diseases, such as Kawasaki disease, a self-limited vasculitis that affects many organs, including the skin and mucous membranes, lymph nodes, blood vessel walls and heart.