MicroRNAs (miRNAs) characterized by small, noncoding RNAs have a fundamental role in the regulation of gene expression at the post‐transcriptional level. Additionally, miRNAs have recently been identified as potential regulators of various genes involved in the pathogenesis of the autoimmune and inflammatory disease. So far, the interaction between miRNAs and T lymphocytes in the immune response as a new and significant topic has not been emphasized substantially. The role of miRNAs in different biological processes including apoptosis, immune checkpoints and the activation of immune cells is still unclear. Aberrant miRNA expression profile affects various aspects of T‐cell function. Accordingly, in this literature review, we summarized the role of significant miRNAs in T‐cell development processes. Consequently, we demonstrated precise mechanisms that candidate miRNAs interfere in Immune response mediated by different types of T cells. We believe that a good understanding of the interaction between miRNAs and immune response contributes to the new therapeutic strategies in relation to disease with an immunological origin.

MicroRNAs (miRNAs) that are characterized by small, noncoding RNA have an essential role in the pathogenesis of human diseases, including cancer. Furthermore, miRNAs, as a new paradigm of epigenetic regulators, play an important role in normal development and cellular function. This literature review summarizes the recurrent mechanism of gene regulation through miRNAs and, consequently, the impact of regulated genes on different cellular processes, including proliferation, metastasis, prognosis, and apoptosis. Additionally, what is important to note is that the expression of miRNAs in various cancer cells is different, and miRNAs have various target genes in various cancers. Accordingly, a proper understanding of gene regulation by miRNAs contributes to new perspectives in miRNA‐based therapeutic strategies. Significance of the study MiRNAs are considered as a crucial regulator of gene expression. The genes also play an important role in the expression of miRNAs; as a result, there is a relationship between them. In recent years, targeted therapy with miRNAs has been a significant challenge. Studying the mechanisms through which miRNAs regulate various cancer cell processes, including apoptosis, proliferation, and metastasis, is very critical in the treatment of cancer through miRNAs. Definitely, a proper understanding of the impacts of aberrant expression of miRNAs on cancer cell processes leads to new therapeutic strategies in the targeted therapy with miRNAs.

: MiRNAs that are characterized by small non-coding RNAs orchestrate the expression of important genes involved in cancer cell development processes including apoptosis, proliferation, angiogenesis, metastasis, and drug resistance at the post-transcriptional level. Dysregulation of miR-9 in various cancers has been reported. Recently, miR-9 has been considered as a key miRNA in various malignancies. However its importance in the pathogenesis of different neoplasms is not yet well defined. Accordingly, this study was conducted in order to clarify the potential roles of miR-9 in in the development of various cancers, prognosis, and treatment approaches. We have shown that a large number of miR-9 targets play fundamental roles in carcinogenesis and that is dysregulated in various cancer cells. Our findings was found aberrant miR-9 expression in a majority of cancers. This review article, generally emphasize on the critical roles of miR-9 in cancer cell progression. Additionally, we intended to investigate the effects of down-regulation or up-regulation of miR-9 in different types of cancers. It is hoped that a good understanding of the regulatory roles of miR-9 in various cancers be helpful for using miR-9 in the clinical settings including prognosis, diagnose, and miRNA based target therapy.