1. Tissue-specific expression of proteins and messenger RNAs -- 2. The DNA of different cell types is similar in both amount and type -- 3. Gene expression -- 4. Regulation at transcription -- 5. Post-transcriptional regulation -- 6. Transcriptional control : chromatin structure -- 7. Transcriptional control : DNA sequence elements -- 8. Transcriptional control : transcription factors -- 9. Gene regulation and human disease -- 10. Conclusions and future prospects