PTPN22 and type 1 diabetes mellitus: We proved the internalization and low toxicity of Lipo-siRNAR620W-PEGF9 (LiposiRNA-PEGF9) in PBMC and their efficacy in halting variant mRNA expression, as well as their functional efficacy by rescuing IL-2 secretion in PBMC of C1858T PTPN22 T1D patients.