PTEN and colorectal carcinoma: However, there is conflicting data regarding the expression and contribution of miRNA-93 in colorectal cancer, as expression has been found to be increased in CRC tissue (169), downregulated by chemotherapeutic drugs (170) and negatively regulates the expression of the tumour suppressor PTEN in SW620 cells (171), yet has also been found to be downregulated in CRC tissue (172–174), with suppression associated with metastatic disease and poor overall survival (175).