poly (i:c), a synthetic double-stranded rna (dsrna) analog, is an immunostimulant that acts as the most potent interferon (ifn) inducer. toll-like receptor- 3 (tlr3) agonist[1].mixtures that included the tlr7/8 agonists r848 or cl075, combined with the poly (i:c), yield 3-d mature dendritic cells [2].commonly used to stimulate immune system activation in vivo. also promotes maturation of hpsc-derived cardiomyocytes[3].[1]. li y g, siripanyaphinyo u, tumkosit u, et al. poly (i:c), an agonist of toll-like receptor-3, inhibits replication of the chikungunya virus in beas-2b cells. virology journal, 2012, 9(1): 114.[2]. spranger s, javorovic m, burdek m, et al. generation of th1-polarizing dendritic cells using the tlr7/8 agonist cl075. the journal of immunology, 2010, 185(1): 738-747.[3]. biermann m1, cai w2, lang d, et al. epigenetic priming of human pluripotent stem cell-derived cardiac progenitor cells accelerates cardiomyocyte maturation. stem cells, 2019, 37(7): 910-923.