def _store_s_exons(subexon_df, seq, subexon, gene, s_exon_id):
    """
    Store s-exon information in subexon_df.

    s_exon_id is the ID of the orthologous exonic region (s-exon) created as
    Cluster_ColCluster.
    """
    seq = seq.replace('-', '')
    length = len(seq)
    query = (subexon_df['SubexonIndex'] == subexon) & (subexon_df['GeneID'] ==
        gene)
    value = subexon_df.loc[query, 'S_exons'].unique()[0]
    if '_' in value:
        subexon_df.loc[query, 'S_exons'] += '/{}'.format(s_exon_id)
        subexon_df.loc[query, 'S_exon_Lengths'] += '/{}'.format(length)
        subexon_df.loc[query, 'S_exon_Sequences'] += '/{}'.format(seq)
    else:
        subexon_df.loc[query, 'S_exons'] = s_exon_id
        subexon_df.loc[query, 'S_exon_Lengths'] = str(length)
        subexon_df.loc[query, 'S_exon_Sequences'] = seq
