Myeloid tissue

[2] Those cells' differentiation (that is, lymphopoiesis) is not complete until they migrate to lymphatic organs such as the spleen and thymus for programming by antigen challenge.

Similarly, myelogenous usually refers to nonlymphocytic white blood cells,[3] and erythroid can often be used to distinguish "erythrocyte-related" from that sense of myeloid and from lymphoid.

Myeloid tissue can also be present in the liver and spleen[5] in fetuses, and sometimes even in adults as well, which leads to extramedullary hematopoiesis.

There is one other sense of myeloid that means "pertaining to the spinal cord", but it is much less commonly used.

Myeloid should not be confused with myelin, referring to an insulating layer covering the axons of many neurons.