Caspase-3 activity corrected for the percentage of epithelial cells, as determined on slides, showed similar results compared with the uncorrected caspase-3 activity in rectal cancer in the study by de Heer et al (2007), and therefore the authors concluded that caspase-3 activity is a prognostic factor for local recurrence in rectal cancer without the previous knowledge of epithelial-stromal ratios in the tumour. Here, CASP3 is linked to rectal cancer.