TP53 and colorectal carcinoma: Exosomal delivery of miR-21-3p and miR-769-3p has been shown to play a role in CRC metastasis to the lung through the activation of fibroblasts in the tumor microenvironment and lung tissue; this process occurs through the formation of premetastatic niches, and the secretion of these types of exosomes increases following p53 R273H mutation [77].