In a pivotal study on sorafenib for the treatment of advanced RCCs, 451 patients with RCCs received sorafenib with no reports of GIP [1], but two (0.2%) instances of GIP occurred in 544 patients with advanced RCC, and in 257 patients with gastrointestinal stromal tumors receiving sunitinib [2,4]. Here, GIP is linked to renal cell carcinoma.