Using 3' RACE PCR and the repeated nested-PCR method, the expression of transcripts of the sex-determining gene SRY was investigated in single lymphocytes from a human adult male and in male tumor cell lines. The gene is functionally transcribed in the early stages of embryogenesis and mRNA is also expressed in adult testes. However, in this study, SRY gene transcripts were also detected in somatic cells of adult male and in tumor cells. Moreover, this mRNA possessed a longer additional untranslated exon. Although expression of the transcripts might not have any functional meaning in these cells, these new findings support the hypothesis that any given human cell can contain illegitimate mRNAs.