 Small interfering RNAs, CERNAs, and microRNAs, MIRNAs, are non-coding RNAs that play important roles in gene regulation. Both types of RNA have been investigated as potential therapeutic agents for treating various diseases such as cancer and infectious diseases. However, they differ in several key aspects, including mechanism of action, physicochemical properties, delivery methods, and clinical applications. CERNAs are highly specific to a single mRNA target while MIRNAs have multiple targets. Additionally, CERNAs are more difficult to deliver than MIRNAs due to their larger size. Despite these differences, both CERNAs and MIRNAs show promise as therapeutic agents and are currently being tested in clinical trials. This article was authored by Jenny K. W. Lam, Michael Y. T. Chow, Yu Zhong, and others.