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Myelopoiesis is a highly active process in the bone marrow (BM) with the production of more than 10¹¹ cells per kg per day. The discovery that synthesis of a proliferation-inducing ligand (APRIL), a member of the TNF superfamily implicated in plasma-cell (PC) survival, starts early in the myeloid lineage reveals that the BM is constitutively rich in APRIL, and may explain the matchless long-term survival of PCs in this organ. However, it also implies the existence of numerous potential survival niches for plasma cells, far exceeding the tiny number of BM resident plasma cells found in the steady state, maintaining the mystery around PC survival niche biology. The figure shows a healthy human BM stained with an antibody recognizing APRIL-producing cells. Insert is a plasma cell stained for CD138. See the article by Matthes et al on page 1838.