PAPPA and breast cancer: Analysis of publicly available data sets was carried out to determine associations between PAPPA and gene sets associated with IGF-1/IGF-1R pathway activation.<h4>Results</h4>PAPP-A was expressed in both the tumour and stromal compartments in breast cancer specimens and was higher in oestrogen receptor (ER)-negative (ER-) than ER-positive (ER+) cases.