def make_gene2files_dict(gene2wells, well2file):
    """Create a dictionary mapping genes to images.

    Parameters
    ----------
    gene2wells : dict, {string: [(int, string)]}
        A dictionary mapping genes to wells.
    well2file : dict, {(int, string): string}
        A dictionary mapping wells to files.

    Returns
    -------
    gene2files : dict, {string, [string]}
        A dictionary mapping genes to files.
    """
    gene2files = {}
    for gene, wells in gene2wells.items():
        gene2files[gene] = [well2file(well) for well in wells]
    return gene2files