Pie charts estimating the relative incidences of deletions and somatic mutations in the key signaling pathways in childhood BCP-ALL. The genes are color coded according to the pathway to which they belong: B-cell differentiation and development, blue; TP53/RB1, red; Ras signaling, purple; JAK/STAT, green, noncanonical pathways and other/unknown genes, black. Deletions in the top chart are shown for the B-cell differentiation and development and TP53/RB1 pathways only and the percentages are estimated from data in 3 publications.^3-5  The PAX5 mutation rate stated by Mullighan et al³  is given (PAX5 mut). The relative incidences of the mutations in the bottom chart are estimated from Zhang et al.¹