In the article by Hu and Chien entitled, “The Cytoplasmic Domain of Stem Cell Antigen CD34 Is Essential for Cytoadhesion Signaling But Not Sufficient for Proliferation Signaling,” which appeared in the February 15, 1998 issue (Vol 91, No 4, pp 1152-1162), a correction should be noted. The sequence of the truncated 3′ primer containing the end of transmembrane domain and the first amino acid of the intracellular domain and two stop codons (underlined) 5′-TATGTCGACATCGATTCATCATTCATCAGGAAATAGCCAGTGATGCCC- 3′ was incorrect. The correct sequence should be 5′-TATGTCGACATCGATTCATCAATTCATCAGGAAATAGCCAGTGATGCCC-3′. We thank Drs Zhixiong Li, Boris Fehse, and Axel Zander for bringing this to our attention.