They need your DNA: but people who give a blood sample have a right to know what it's used for.
D001782:Blood Donors / Q000523:psychology*; D001955:British Columbia; D004247:DNA / Q000235:genetics; D008192:Deception; D036281:Genetic Research / Q000941:ethics*; D017408:Guidelines as Topic; D006801:Humans; D007198:Indians, North American / Q000235:genetics* / Q000523:psychology*; D007258:Informed Consent / Q000941:ethics*; D018907:Privacy; D012108:Research Personnel / Q000941:ethics; D006113:United Kingdom; D014481:United States
D004247:DNA