Amplification of these receptors, individually and cooperatively, has been shown to promote tumour cell growth and is associated with breast carcinogenesis.41, 42, 43 Moreover, exogenous delivery of IGF‐1 significantly enhanced HMEC proliferation, suggesting the adoption of the IGF‐1 responsive phenotype observed by Castaño et al in triple negative tumours. Here, IGF1 is linked to neoplasm.