Nature Immunology, Published online: 10 April 2024; doi:10.1038/s41590-024-01808-x

Cupedo and colleagues show that neutrophils promote a tumor-supportive microenvironment via a self-amplifying interaction between neutrophils and bone marrow stromal cells. This scenario creates a promyeloma niche that is difficult to treat despite targeted therapies directed at the myeloma cells.