In a post-hoc single-cell RNA sequencing analysis, data from patients with RMC before and after nivolumab plus ipilimumab treatment indicated that immune checkpoint therapy (ICT) triggered an interferon-γ response that induced a “myeloid mimicry” program in tumor cells, regulated by the CEBPB / p300 axis and linked to proliferation and hyperprogression. Here, CEBPB is linked to neoplasm.