Virus is one of the largest global health concerns. The ability of virus to rapidly evolve underlies the challenge to achieve a virus-free world. The two major problems are 1) immune evasion, which can lead to vaccine escape, and 2) host jump, which can lead to pandemic. Fortunately, not all viral mutations have a deleterious consequence to public health. Most viral mutations disrupt protein functions that are essential in the virus life cycle. Therefore, a significant portion of the viral genome is under strong evolutionary constraints. Our research interest is to characterize virus evolution, including both positive selection pressures (immune evasion and host adaptation) and negative selection pressures (virus-host molecular interactions). While our main focus has been on influenza virus, we occasionally work on other viruses such as HIV, HCV, and SARS-CoV-2 Research Interests Research Topics Bioinformatics, Host-Pathogen Interactions, Molecular Evolution, Molecular Immunology, Protein Structure, Virology Disease Research Interests Cancer, Infectious Diseases