1. Basic concepts of thiol chemistry and biology 2. Chemical basis of cysteine reactivity: Acidity and nucleophilicity 3. Computational functional analysis of cysteine residues in proteins 4. Global approaches for protein thiol redox state detection and quantification 5. Thiol oxidation by biologically-relevant reactive species 6. Thiyl radicals: formation, properties and detection 7. Detection of the oxidation products of thiols: disulfides, sulfenic, sulfinic and sulfonic acids 8. Biochemistry and detection of S-nitrosothiols 9. Thiol modification and signaling by biological electrophiles10. Thioredoxin and glutathione reductases 11. Functional plasticity in the thioredoxin family: FeS-thio- and glutaredoxins 12. Glutathione and glutathione-dependent enzymes 13. Thiol and selenol-based peroxidases: Structure and catalytic properties 14. Thiol peroxidase-based redox relays 15. Compartmentalized disulphide bond formation pathways 16. Disulfide bond formation in Escherichia coli 17. Thiol-based redox probes18. Selenocysteine-containing proteins19. Overview of cysteine metabolism20. Hydrogen sulfide and persulfides 21. The role of thiols in iron-sulfur cluster biogenesis 22. Thiol-based redox control in chloroplasts 23. Sugar-based cysteine thiols recruited for oxidative stress defence and redox regulation 24. Polyamine-based thiols in pathogens 25. Thiols in blood26. A thiol chemistry perspective on redox medicine 27. Therapeutic applications of low-molecular-weight thiols and selenocompounds 28. Thiol targets in drug development to combat bacterial infections