PTX3 and colorectal carcinoma: Interestingly, chromatin immunoprecipitation analyses revealed that treatment with the methylation inhibitor 5-AZA-dC and TNF-α elevates transcription-activating histone marks (H3K4me3, H3K27ac, and H3K9ac) at the PTX3 promoter in CRC cells, without altering H3K27me3 levels (30, 32).