MMP7 and myeloid sarcoma: To identify cellular sources of (pro)MMP7 expression and release, and to explain its impaired expression in chronic MS lesions, we examined the presence MMP7 in lysates and in conditioned medium of cultured microglia and astrocytes, as well as bone marrow‐derived macrophages (referred to as “macrophages”) under resting (control) and/or MS‐relevant conditions that do not affect cell viability.