An increase in collagen-1 has been shown to shift the activity of signalling cascades in tumour epithelium from signal transducer and activator of transcription 5 (STAT5), a prolactin mediator associated with a milder course of the tumour, towards ERK1/2 and AKT pathways, which are poor prognostic markers [78]. This evidence concerns the gene AKT1 and neoplasm.