RISC is primarily guided by small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs (siRNAs). These small RNAs are processed from longer precursor molecules by the enzyme Dicer. Once incorporated into RISC, the small RNA serves as a template for sequence-specific recognition of target mRNA. Upon binding to the target mRNA, RISC can either cleave the mRNA or inhibit its translation, effectively silencing the gene.