Mean PCT values of sera corresponding to positive and negative SF samples were 35.42±61.03 ng/ml and 0.84±1.67 ng/ml, respectively (p<0.0001); similarly, mean PCT values of sera corresponding to BC positive and negative for a pathogen were 23.14±51.56 ng/ml and 2.79±16.64 ng/ml, respectively (p<0.0001). This evidence concerns the gene CALCA and breast cancer.