Differential expression analysis is a research area in molecular biology and bioinformatics that focuses on identifying genes or proteins that are differentially expressed between different conditions or experimental groups. This analysis helps to understand the biological processes or pathways that are altered in response to certain stimuli, diseases, or genetic mutations. Differential expression analysis is often performed using high-throughput technologies such as microarrays or RNA sequencing, and involves statistical methods to identify genes that show significant changes in expression levels. This information is crucial for understanding the underlying mechanisms of biological processes and for identifying potential biomarkers or therapeutic targets.