For example, KLK7 positivity rates of ≥ 90% have been described for breast cancers [17], ovarian carcinomas [12–14], oral squamous cell carcinomas [20, 22, 25], adenocarcinomas of the colon [21], adenocarcinoma of the cervix [23], and different subtypes of renal cell carcinomas [27] in individual studies. Here, KLK7 is linked to breast cancer.