Thus, FOXM1 expression is positively correlated (Pearson’s r = 0.712, p < 10− 4) with myeloma cell proliferation in 244 Bz-treated patients available at GSE9782 [18], using the global gene expression-based proliferation index (GPI) of myeloma devised by Bergsagel et al. [19] as proxy of actual tumor cell proliferation (Fig. 2d). Here, FOXM1 is linked to plasma cell myeloma.