ITGA9 and cancer: Fig. S1B shows the expression of the pair formed by the ITGB1:ITGA9 complex and the SPP1gene in patient MGH42; the ITGB1:ITGA9 complex should be expressed by cancer cells. However only 1 of the 2 members of the complex is highly expressed in the tumor cluster (ITGB1) while the expression of the other partner (ITGA9) is almost undetected.