NOS2 and neoplasm: By recruiting the repressive chromatin-remodeling regulator Mi-2 and the repressive histone modification H3K27me3 at Nos2 gene promoter, sdnRNA3 represses the transcription and expression of iNOS by repressing chromatin accessibility at the promoter of iNOS gene (83).Since TAMs are well-established to suppress anti-tumor immunity, these findings suggest nicely that snoRNA and sdnRNA3 could play pivotal roles in the formation of an immunosuppressive microenvironment.