The human c-Ha-ras2 gene, one of two known members of the Harvey ras family, is reportedly located on the X-chromosome and has lost introns (1, 2). There has heretofore been no information on its precise gene structure and oncogenic potential. We have determined the nucleotide sequence of the c-Ha-ras2 and demonstrate that it is a processed pseudogene surrounded by several direct repeats and contains numerous base substitutions as well as a notable mutation (AGT at codon 12 of the p21 protein) responsible for oncogenic conversion of the known ras genes (3-8).