The top protein biomarker Stratifin (14-3-3 protein sigma, and additionally noting 14-3-3 proteins delta and zeta) was previously identified as downregulated in a comparison of pooled saliva specimens from patients with breast cancer (stage 2 invasive ductal carcinoma of the breast, IDC) compared to controls [46]; Stratifin has a broad involvement in various diseases and in general the 14-3-3 protein family plays a role in DNA damage repair, inflammation and apoptosis [47]. Here, SFN is linked to invasive ductal breast carcinoma.