HLA-B7 allele of human HLA class I major histocompatibility (MHC) antigen indicates higher risk of breast cancer and cervical cancer. Expression of HLA-B7 together with HLA-B27 is associated with increased susceptibility to spondyloarthropaties. Flow cytometry detection of these two alleles is being used to screen for patients, who suffer from inflammatory disorders affecting the sacroiliac and intervertebral joints, such as ankylosing spondylosis (AS). The HLA-B7 antigen (11 alleles) is expressed in 22% of healthy Caucasian individuals.