PIK3CA and cancer: The JM1-24-3 full-length mAb and F (ab’)2 treatment RPPA data together with IPA analysis revealed that JM1-24-3 binding to MUC18 initiated signaling in fundamentally important canonical cancer pathways, including PI3K/AKT and neuregulin; the top associated upstream regulators were TP53, MYC, ESR1 and others; the most important molecular and cellular functions impacted were those associated with cell death and survival, cellular development, and cellular growth and proliferation (Supplementary Fig. S3A).