“…that the Ca2+ uniporter A of Fig. 14 probably does not exist in mitochondria, but that calcium is probably translocated by the symporters B and C , and possibly by other similar systems yet to be discovered, is not generally accepted. Indeed, evidence and arguments against our experimental findings and interpretations have been presented by Lehninger and colleagues [95,103], by Azzone and colleagues [104], and by Crompton, Hediger and Carafoli [105]. Brian Chappell has told me privately that his paper during this FEBS meeting will also describe observations from which he concludes that calcium is translocated, not with one positive charge, as we [96] and Akerman [97] have found, but with two positive charges, as was formerly supposed.…”