PIK3R1 (Phosphoinositide-3-Kinase, Regulatory Subunit 1): PIK3R1 encodes a regulatory subunit of the phosphoinositide 3-kinase (PI3K), which is a part of important signaling pathways involved in cell growth, proliferation, and survival. Mutations in this gene are implicated in several cancers and are a target for cancer therapies. It also plays a role in insulin signaling and is associated with diabetes and metabolic syndromes....