Western blot analysis of Bcl-xL expression in human normal and tumoral liver. Lane 1: hepatocellular carcinoma (male, age 65); lane 2: adenocarcinoma (male, age 52); lane 3: cholangiocellular carcinoma (male, age 46); lane 4: normal liver (male, age 24); lane 5: normal placenta (female, age 24). Bcl-xL immunoreactivity (26 kD) was observed in two out of three liver cancer samples (lanes 1–3). Normal samples (lane 4–5) had no signal for Bcl-xL expression. Note that GADPH protein levels varied between normal tissues and cancer liver specimens and did not correlate with the mRNA levels predicted by the computer-based screen. The expression of tubulin was used as control for equal protein loading.