The growing body of evidence demonstrates that many BPA substitutes are indeed “regrettable” in a sense that they are by far not free from potential endocrine activities. Some analogues, most notably BPAF, may even show higher potency to induce certain effects compared to BPA. Of interest, BPAF was also found to have much higher half-lives in farm and forest soils in the environment compared to BPA and BPS, suggesting a higher potential for environmental effects. According to a recent market survey in the EU, a large variety of bisphenols may be currently in use (FPF reported ), with many BPA analogues having insufficient data to judge on their potential EDC properties (FPF reported ). In light of this, several organizations, for example the Green Science Policy Institute and the International Chemical Secretariat , have called for risk assessment of bisphenols as a class, not substance by substance.
Ellerby et al demonstrated that caspases, or "cysteine protease cell-death executioners", may act on the gene product (ie, androgen-receptor protein) resulting from the trinucleotide-repeat expansions, which act as substrates. Caspase cleavage affects proteins with the abnormal expanded polyglutamine tracts, resulting in cell death. Ellerby et al concluded that caspase cleavage is an important step in cytotoxicity (ie, neuronal cell death). [ 40 ] High circulating levels of androgens in men might precipitate the motor neuron degeneration observed in KD. [ 41 ] Ranganathan et al have shown that the mutant protein may affect mitochondrial function. [ 42 ]
Many hormones and their structural and functional analogs are used as medication . The most commonly prescribed hormones are estrogens and progestogens (as methods of hormonal contraception and as HRT ),  thyroxine (as levothyroxine , for hypothyroidism ) and steroids (for autoimmune diseases and several respiratory disorders ). Insulin is used by many diabetics . Local preparations for use in otolaryngology often contain pharmacologic equivalents of adrenaline , while steroid and vitamin D creams are used extensively in dermatological practice.