Triad1 is highly expressed in granulocytes. (A) Northern blot hybridization using Triad1 clone 14-5 as a probe detects high Triad1 expression in mature granulocytes compared with complete bone marrow and T cells. (B) Triad1 quantitative RT-PCR detects high expression in granulocytes and low expression in immature CD34⁺ and T cells. Data are from 2 samples from unrelated healthy volunteers. Expression in CD34⁺ cells was set at 1.0, and values were normalized for porphobilinogen deaminase (PBGD) expression as described.²⁶  (C) Triad1 real-time PCR detects high expression in peripheral blood compared with bone marrow (expression in total bone marrow was set at 1.0). Among nonhematopoietic tissues highest expression was observed in fetal brain.