Specifically, anti-CTLA-4 treatment typically upregulates the expression of co-stimulatory molecules CD80/CD86 and MHC II on dendritic cells, whereas butyrate inhibits these upregulations, as well as the expression of ICOS on T cells (a T cell activation marker) and the accumulation of tumor-specific and memory T cells, thereby dampening immune activity. The gene discussed is ICOS; the disease is neoplasm.