MAP2K4 and lip and oral cavity carcinoma: Moreover, gallic acid in various studies showed the same trend on MAPK inhibition; for example, gallic acid at 25–75 μM suppressed ERK1/2 phosphorylation in osteosarcoma cells [54], and MAPK involving proteins ERK1/2 and c-Jun NH2-terminal kinase 1 and 2 (JNK1/2) showed reduced phosphorylation after treatment with gallic acid at 30–60 μM in oral cancer cells [55].