While investigating how white blood cells known as B cells develop, researchers have discovered that genes from the Phosphatidylinositol 3-kinase (PI3Ks) family of enzymes are critical in enabling the B cells to produce antibodies in the spleen and lymph nodes. PI3Ks are involved in a diverse range of activities inside cells, generating signalling molecules to control cell growth, proliferation, motility, survival and intracellular trafficking. Faults in these processes can lead to the development of cancer; consequently the PI3Ks are currently among the most hotly pursued drug targets in the pharmaceutical industry.