Overall, we demonstrate that the CML BM niche drives high expression of genes related to alternatively activated macrophages such as Tgfbi and Lgals1. We identified that both subpopulations of CML-exposed macrophages harbour an immature transcriptional signature, which appears to cluster with an immature subpopulation found under homoeostatic conditions. Here, TGFBI is linked to chronic myelogenous leukemia, BCR-ABL1 positive.