RAC1 and diffuse large B-cell lymphoma: We found that interaction with DLBCL cells induced the accumulation of PDPN into lipid rafts where it colocalized with its inhibitory partner CD44 (Supplemental Figure 3, J and K), reduced actin-dependent contractile signaling (Supplemental Figure 3L), and triggered a switch in Rho A–to–Rac-1 activation (Supplemental Figure 3, M and N), in keeping with FRC stretching (32).