We analysed tumours for apoptosis (TUNEL+, 7.3 ± 0.9 vs. 6.5 ± 1.1%, mean ± S.E.M., N = 4) and proliferation (phospho-H3+, 3.1 ± 0.2 vs. 3.5 ± 0.2%) levels in Ccr2RFP/RFP vs. Ccr2+/+ mice at endpoint, but did not detect any significant difference between these groups (Supplementary Fig. 6). The gene discussed is CCR2; the disease is neoplasm.