Sex has a major role in determining susceptibility and progression of disease, with increasing evidence of male and females differing in their basic physiology that lends to these differences. As sex differences are generated through the interaction of numerous biological and environmental forces, it remains to be understood how these factors contribute to disease and which variables could help in diagnosis and therapies. Biological states such as cell-type, cell-state, tissue, sex, disease, or age, are all encoded in a sample’s transcriptional profile, as measured by assaying mRNA levels. Transcriptomic data has therefore been used as proxy for functional phenotypes. Sex-biased gene expression has been observed in tissues and cell-types, suggesting that, transcriptionally, sex differences arise from regulatory differences of these genes. Alongside this, changes in the immune system with age is a well known phenomenon, and assessing these differences in conjunction with sex will reveal their impact.