HSP90AA1 and Hyponatremia: This suggests some sort of synergism, as erlotinib and docetaxel have rarely been associated with hyponatremia outside situations with a known hyponatremia incidence risk, as incurred by patients with non-small cell lung cancer or patients treated with cisplatin (the erlotinib-combination trial in fact included patients with lung cancer, but hyponatremia occurred exclusively in patients administered the HSP90 inhibitor at high dose [12]).