HES1 and neoplasm: Notably, inhibition of macrophages using the anti-CSF1R antibody was as effective in delaying tumor growth as was conditional KO of Hes1. After observing a comparable reduction in tumor volume between treatment with an antibody against CSF1R and the absence of Hes1 in myeloid lineages, we reached the conclusion that the conditional knockout of Hes1 leads to a TAM-dependent decrease in tumor volume, indicating that TAMs play a significant role in mediating the observed anti-tumor effect.