Figure 1

The majority of MGF is expressed by the BM environment of patients with MM. 42/51 MGF genes that are expressed in MMC and/or in the environment are represented in a Venn diagram according to their overexpression in each BM population compared to the others (p ≤ .05, fold-change ≥ 2). *Indicates that those 5 genes were expressed in MMC and environment cells, but without any change in signal between present or absent call (data not shown). This suggests that either those probe sets poorly work or their expression level is at the limit of sensitivity and thus can hardly be detected by Affymetrix probe sets. ^# Those genes were not statistically significantly overexpressed in MMC, but they displayed an absent call in all environment population (see additional file 2, table S-I) and they were thus defined as "myeloma MGF".