Interestingly, downregulation of PDGF-BB by Pdgfb-specific shRNA, which effectively inhibited the Pdgfb mRNA level (Supplementary Fig. 1a), markedly ablated TAMs in tumour tissues (Fig. 1b), suggesting that PDGF-BB was primarily responsible for TAM recruitment in this human xenograft model. The gene discussed is PDGFB; the disease is neoplasm.