Drosha is a ribonuclease (RNase) III double-stranded RNA-specific ribonuclease and subunit of the microprocessor protein complex, which catalyzes the initial processing step of microRNA (miRNA) synthesis.  Drosha plays a critical role in microRNA biogenesis, essential regulators of gene expression. Located primarily in the nucleus, Drosha processes primary microRNA transcripts (pri-miRNAs) into precursor microRNAs (pre-miRNAs), a crucial step in microRNA maturation. This processing regulates gene expression, as microRNAs inhibit target mRNAs, influencing cellular processes like development, differentiation, and stress response. Drosha functions within a multi-protein complex including DGCR8, enhancing specificity and efficiency in recognizing and cleaving pri-miRNAs. Drosha and DGCR8 interaction demonstrates how protein-protein interactions regulate RNA processing, revealing complex mechanisms governing gene expression and cellular function.