def get_heatmap_y_sample_sizes(parsed_mutations, sample_sizes):
    """Get sample size y axis values of heatmap cells.

    :param parsed_mutations: A dictionary containing multiple merged
        ``get_parsed_gvf_dir`` return "mutations" values.
    :type parsed_mutations: dict
    :param sample_sizes: A dictionary containing multiple merged
        ``get_parsed_gvf_dir`` return "sample_size" values.
    :type sample_sizes: dict
    :return: List of sample size y axis values
    :rtype: list[str]
    """
    ret = []
    for strain in parsed_mutations:
        ret.append(sample_sizes[strain])
    return ret