Streptococcus pyogenes (group A Streptococcus, GAS) is a gram-positive bacterium and is one of the most common pathogens that causes cellulitis and necrotizing fasciitis. The mortality rate of necrotizing fasciitis is very high, ranging from 30%-70%. Our study focuses on the investigation of the pathogenic mechanism of GAS necrotizing fasciitis, specifically focusing on the characterization of the phenotype and regulatory network of invasive GAS strains. The lab also studies human pathogenic bacteria, such as Staphylococcus argenteus and Clostridium innocuum, in cooperating with research groups in Linkou Chang Gung Memorial Hospital.