In humans, COX-2 is raised in both ductal carcinoma in situ (DCIS, Half et al, 2002) and invasive breast cancer (Spizzo et al, 2003; Boland et al, 2004; Figure 1) and appears to be associated with higher proliferation, lower apoptosis and increased new blood vessel formation (Kirkpatrick et al, 2001; Boland et al, 2004). The gene discussed is PTGS2; the disease is invasive breast carcinoma.