Myc and p110α immunoblots in parental and stable cell lines (S1); Quantitation of immunoblots from Figure 1 (S2); Expression of GPCR-uncoupled or kinase-dead p110β in MDA-MB-231 cells has no effect on breast cancer cell proliferation (S3); Gβγ binding to p110β is required for macrophage-stimulated breast cancer cell migration (S4); Gβγ binding to p110β is required for macrophage-stimulated invasion in T47D cell line (S5).