PTPN22 and neoplasm: Oncomirs, mutated tumor suppressor genes, and a number of other genes concerned in tumor progression are smart targets for gene silencing by RNAi-based therapy.24 The most important advantage of RNAi in cancer therapy is targeting multiple genes of assorted cellular pathways concerned in tumor progression.25 Here, we specifically investigated the effects of PTPN22 silencing in human acute T-cell leukemia cell line (Jurkat cell) and its effect on the expression of miR181a and miR181b.