NUMA1 and breast cancer: Another FDA-approved BC protein biomarker is NMP22 (nuclear matrix protein 22) on the basis of which two diagnostic tests have also been developed: the quantitative NMP22 ELISA (sensitivity and specificity of 69% and 77%, respectively) and the qualitative NMP22 BladderChek test (sensitivity and specificity of 58% and 88%, respectively), which have been validated for initial diagnosis.