The phosphatidylinositol-3-kinase (PI3K) signaling pathway plays a crucial role in B cell activation, differentiation, and survival. It also regulates cell growth, motility, survival, metabolism, and angiogenesis, and contributes to development of tumors and drug resistance. PI3K inhibitors, like idelalisib and alpelisib, cause cell death and inhibit the proliferation of malignant cells.