The landmark paper discussed in this chapter is ‘The capsaicin receptor: A heat activated ion channel in the pain pathway’, published by Caterina et al. in 1997. The identification of the molecular basis for the sensitivity of a major proportion of nociceptive primary sensory neurons for capsaicin, the pungent agent in chilli pepper, was undoubtedly one of the most significant pain-related discoveries in the twentieth century, for at least three reasons. First, the mechanism for capsaicin-induced responses could unequivocally be explained. Second, the discovery heralded the starting point for the development of a highly promising, mechanism-based means of analgesia. Third, the discovery also sparked studies which resulted in the discovery of the major cation channel family, the transient receptor potential (TRP) ion channel family, several members of which have also become putative targets for the development of analgesics.