MAPK1 and non-small cell lung carcinoma: It has recently been found that overexpression of OPN sufficiently reduces the efficacy of cetuximab (CTX) in NSCLC cells, by upregulating MAPK pathway-related proteins phosphorylated mitogen-activated protein kinase (p-MEK) and p-ERK, so presumably, OPN may confer resistance to CTX via activating the MAPK signalling pathway [76].