Its physiological role is related to brain embryogenesis, but fusion with other genes results in increased tyrosine kinase activity leading to tumor development through PLC, JAK-STAT, PI3K-AKT, mTOR, SHH, JUN-B, CRKL-C3G, RAP1, GTPase and MAPK cascades. The gene discussed is PIK3CB; the disease is neoplasm.