TRPV1 and cancer: The double-staining of TRPV1 and TLR4 exhibited no alteration in the expression of TRPV1 +IR cells on day 3 after perineural cancer cell inoculation but an increase in TLR4 +IR cells was detected on the same day, followed by a decrease in their expression at 7 and 14 days after tumor injection for both receptors.