Trough levels of ipilimumab in serum as a potential biomarker of clinical outcomes for patients with advanced melanoma after treatment with ipilimumab ====================================================================================================================================================== * Yoshinobu Koguchi * Noriko Iwamoto * Takashi Shimada * Shu-Ching Chang * John Cha * Brendan D Curti * Walter J Urba * Brian D Piening * William L Redmond