Fig. 1

Identification of the mitochondrial depleted adult T-ALL tumours. A: Heatmap of normalized expression levels in our pooled adult T-ALL dataset, for 161 genes available in the human gene set “GOBP ELECTRON TRANSPORT CHAIN” (database MSigDB, collection C5: “Ontology/Gene Ontology/Biological Process”). The T-ALL samples are ordered accordingly to the average normalized expression level across the 161 genes. The group “MT-”, shown in blue, corresponds to 20% of T-ALL samples (n = 26) with low expression levels of these genes. The group “MT+”, shown in red, corresponds to 20% of T-ALL samples (n = 26) with high expression levels. The expression levels were normalized using the z-scores. B: Volcano plot showing the results of the differential analysis performed in the group “MT+” versus the group “MT-”. The x-axis represents the log2 value of the fold change calculated between the average expression levels in the groups “MT+” and “MT-”. The y-axis shows the -log10 of the adjusted p-value obtained with the two-sided t-test between the distributions of expression levels in the groups “MT+” and “MT-”. Significantly down-regulated genes in the group “MT+” versus the group “MT-” are plotted in blue dots. Significantly up-regulated genes are shown in red dots. We considered that the expression levels between the groups “MT+” and “MT-” were significantly different if the adjusted p-value < 0.05 and the absolute value of the fold change > 2. The detailed results of the differential analysis are available in Supp. Table S1. C: Heatmap of the differential expression profiles of the “MT+” group versus the “MT-” group in the pooled adult T-ALL dataset, with the differentially expressed genes presented in Fig. 1B. The hierarchical clustering was performed using Euclidian-based distance with Ward’s linkage for samples and Pearson correlation for genes