While systems immunology has advanced, understanding the healthy female immune system remains incomplete. The FemmunityX research team focuses on the variation of the female immune system in health and disease, aiming to understand its role in immune sex differences. The interaction between the immune and endocrine systems is particularly dynamic in metabolic conditions like obesity and insulin resistance. We hypothesize that these changes create a dynamic range of immune-sex differences. Our goal is to investigate how endocrine and metabolic fluctuations shape the female immune system and contribute to immune sex differences. Using systems biology, we study immune-metabolic sex differences in various populations, including collaborations in Tanzania and Bonn. Using advanced bioinformatics to characterize the female immune-metabolic systems, we analyze transcriptome, metabolome, and proteome data.