CCR2 and neoplasm: We found that tumours injected in Ccr2RFP/RFP mice had decreased apoptosis (TUNEL+, 2.4 ± 0.2% vs. 3 ± 0.2%, mean ± S.E.M., N = 13–14) and increased proliferation (phospho-histone H3+, 377 ± 15 vs. 316 ± 12 cell mm−2) compared to Ccr2+/+ mice (Fig. 4e, f).