We assessed the protein expression levels of bcl-2, bax, bcl-xL, and bcl-xS in a group of 51 endometrial cancers and 8 normal samples as well as in 59 cervical neoplasms and in 15 normal cervical tissues. Neoplastic endometria (median, 1.30 absorbance units [AU]; range, 0.13-7.26 AU) had slightly higher bcl-2 levels than did normal tissue (median, 0.83 AU; range, 0.29-1.90 AU; P < .068), whereas bcl-2 was lower in neoplastic (median, 3.59 AU; range, 0.13-19.86 AU) than in normal cervical samples (median, 8.45 AU; range, 2.09-15.04 AU; P < .010). Bcl-xL levels were higher in endometrial carcinoma (median, 1.23 AU; range, 0.03(4.29 AU) than in normal tissues (median, 0.56 AU; range, 0.46-1.48 AU; P < .048), whereas no significant difference was observed in cervical tissues. Bax levels did not show any variation in either system. The protein bcl-xS was marginally detectable in only a few samples. In endometrial carcinoma, bcl-2 and bcl-xL levels were correlated inversely (r = -0.27; P < .054), whereas in cervical cancer, they were correlated directly (r = +0.40; P < .002). The different expression patterns of bcl-2 family members in endometrial and cervical tissues confirm the hypothesis of a strictly tissue-specific regulation of these proteins.