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We would like to thank Dr Yu and colleagues1 for sharing their thoughts and intruiging data on Toll-like receptors (TLRs) and hepatocellular carcinoma (HCC). The role of TLRs in cancer is indeed an interesting, yet highly complex topic, with TLRs probably exerting both antitumour and protumour effects depending on tumour stage, tumour type and specific circumstances.2

Antitumour effects of bacterial infections were already observed in the 18th and 19th century in patients with advanced cancers.2 In the late 19th and early 20th century, Coley used heat-killed bacteria to treat a large number of patients with sarcomas of the bone, leading to a considerable rate of tumour regression and even complete cure in some patients, yet with overall variable …