STAT3 and lip and oral cavity carcinoma: A study by Zhen et al. showed that curcumin inhibited the proliferation of oral cancer cells in a dose-dependent manner along with inhibition of cancer cell invasion and inhibition of activation of both EGFR and EGFR downstream signalling molecules PKB, mitogen-activated protein kinase 1 (MAPK1/2), and signal transducer and activator of transcription 3 (STAT3) [7].