OR51E2 and neoplasm: OR7C1 maintains colon cancer initiating cells, OR51B5 leads to the inhibition of cell proliferation in K562 cells, OR51E1 acts as a tumour biomarker for lung carcinoids (LC) in somatostatin receptor-negative tumour patients, OR2J3 activation by helional induces apoptosis and inhibits cell proliferation in non-small-cell lung cancer, OR51E2 acts as a biomarker for prostate cancer (Dalesio et al., 2018) and OR10H1 is the potential biomarker for urinary bladder cancer (Weber et al., 2018a).