Is a quantification of sex hormone binding globulin. In men the test is used in when investigating testosterone deficiency.  The SHBG glycoprotein binds to circulating estradiol and testosterone, low levels of SHBG may be implicated in breast cancer etiology. The trait is sex hormone-binding globulin measurement (Experimental Factor Ontology term EFO_0004696). Also known as: SHBG level, SHBG levels.