def fetch_hpo_files(genes_to_phenotype=False, phenotype_to_genes=False, hpo_terms=False):
    """
    Fetch the necessary HPO files from http://compbio.charite.de

    Args:
        genes_to_phenotype(bool): if file genes_to_phenotype.txt is required
        phenotype_to_genes(bool): if file phenotype_to_genes.txt is required
        hpo_terms(bool):if file hp.obo is required

    Returns:
        hpo_files(dict): A dictionary with the necessary files
    """
    LOG.info("Fetching HPO information from http://compbio.charite.de")

    hpo_files = {}

    if genes_to_phenotype is True:
        hpo_files["genes_to_phenotype"] = fetch_genes_to_hpo_to_disease()
    if phenotype_to_genes is True:
        hpo_files["phenotype_to_genes"] = fetch_hpo_to_genes_to_disease()
    if hpo_terms is True:
        hpo_files["hpo_terms"] = fetch_hpo_terms()

    return hpo_files