def are_conserved_aas(aa1, aa2):
    """Determines if two amino acids are conserved based on the paper
    'Structural Determinants in the Sequences of Immunoglobulin Variable
    Domain'"""
    groups = ['WFILMVC', 'PYTHSAG', 'KEQNRD']
    for g in groups:
        if aa1.upper() in g and aa2.upper() in g:
            return True
    return False
