In particular, sensitivity of IgYs for detection of endogenous KLK6 and lack of crossreactivity with other KLKs and unrelated proteins was assessed by analyzing whole cell lysates and supernatants isolated from MDA-MB-468 breast cancer cell line that expresses the KLK5, KLK6 and KLK10 proteins. This evidence concerns the gene KLK6 and breast carcinoma.