Interestingly, overexpression of HDAC1 in CRC correlated with significant decrease in survival and was able to predict poor patient prognosis.30 Further, in cases where CRCs are characterized by microsatellite instability (MSI) (approx. 15% of CRCs), which occurs due to deficiency in the mismatch repair pathway, 5-FU treatment was not effective and showed resistance as compared with microsatellite stable CRCs. This evidence concerns the gene HDAC1 and colorectal carcinoma.