TNFSF10 and anemia (phenotype): These effects of MM cells on the BM can explain the presence of anaemia in MM patients since the infiltrating MM cells can be disadvantageous to marrow erythropoietic niches, which could lead to erythroid cell apoptosis due to MM cells producing specific cytokines, such as Fas ligand (FL), tumour necrosis factor (TNF) and TNF-related apoptosis-inducing ligand (TRAIL) [21].