A retroviral strategy for expression cloning factors that suppress alpha(1,3)fucosylation in LEC11B cells was developed, and several cDNAs that reverted the LEC11B glycosylation phenotype were isolated. cDNAs that arose most frequently and independently encoded SLC35C2, a putative GDP-fucose transporter (also termed CGI-15 or Ovcov1); Cd63, a tetraspanin membrane protein; and Hdac5, a histone deacetylase.