Schematic of the final algorithm structure and genes. The algorithm consists of overlapping gene expression functions for men and women with a sex-specific linear age function for the former and a non-linear age function for the latter. The genes in each term and their weights are shown. For the gene expression components, 16/23 genes in 4 terms are gender independent: Term 1 - neutrophil activation and apoptosis, Term 3 - NK cell activation to T cell ratio, Term 4, B to T cell ratio, and Term 5 -AF289562 expression normalized to TFCP2 and HNRPF. In addition, Term 2 consists of 3 sex-independent neutrophil/innate immunity genes (S100A8, S100A12, CLEC4E) normalized to overall neutrophil gene expression (AQP9, NCF4) for women and to RPL28 (lymphocytes) for men. The final male specific term is the normalized expression of TSPAN16. Algorithm score is calculated as described (Additional file 1).