PIK3CB and neoplasm: Subsequently, Whale et al. reported detection of PIK3CB (E1051K) in breast, lung, oesophagus, stomach and kidney tumours and showed that the protein it encoded drove phosphoinositide 3-kinase (PI3K) signalling and tumour cell growth and migration, indicating that PIK3CB (E1051K) is a gain-of-function mutation [28].