def get_gene_class(gene):
    """
    Return the class of a gene.
    Available options are Core or Non-core.
    """
    core_genes = ['pif-0', 'pif-1', 'pif-2',
                  'pif-3', 'pif-4', 'pif-5',
                  'pif-6', 'pif-7', 'pif-8',
                  'dnapol', 'desmoplakin',
                  'dnahel', 'alk-exo', 'p33',
                  'lef-1', 'lef-2', 'lef-4',
                  'lef-5', 'p18',
                  'lef-8', 'lef-9', 'p47',
                  'vlf-1', '38k', 'ac53-like',
                  'p40', 'p6.9', 'vp1054',
                  'vp39', 'ac81-like', 'gp41',
                  'odv-e18', 'odv-e25', 'p45',
                  'odv-ec43', 'p49',
                  'ac78-like', 'odv-ec27'
                  ]
    if gene in core_genes:
        return "Core gene"
    else:
        return "Non-core gene"