FGFR4 and pituitary tumor: Although the FGFR4 was found to be an aggressive pituitary tumor marker [13,29,30], the study by Qian et al. [13] found that cytoplasmic expression of FGFR4 protein was observed in 57.8% of Japanese cases and 62.8% of Canadian cases, while FGFR4 reactivity was absent in all 10 normal adenohypophyseal tissues analyzed.