MAPK1 and colorectal cancer: In colorectal cancer, high expression of miR-21-5p modulated malignant phenotypes, such as proliferation, anti-apoptosis, cell cycle progression, and cell invasion, through the regulation of PTEN protein expression (Wu et al., 2017).The target genes of the microRNAs discussed in this study regulate important pathways such as the mitogen-activated protein kinase pathway MAPK (ERK1/ ERK2),which when altered, can participate in the initiation and progression of cancer, and which have been recognized as important targets for therapy against various cancers (German et al., 2017).