A study in humans demonstrated that the piR-hsa-26591 is a potential biomarker for distinguishing saliva from vaginal secretions, as it was validated to be significantly more highly expressed in vaginal secretions (15-fold higher) than in saliva with no overlap in ΔCq value quartiles [Wang et al. DOI:10.1016/j.fsigen.2019.07.015]. A review further confirmed its potential for distinguishing these two body fluids in forensic science applications [Li et al. DOI:10.1093/fsr/owad003].