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English: Figure 1. (A) Mechanism of action of FGFR inhibitors and FGFR signaling pathway: FGFR inhibitors act by inhibiting the FGFR downstream signaling pathway (B) Pathophysiology of FGFR-inhibitor-associated hyperphosphatemia: In kidneys, FGFR inhibitors target FGF23 ligand and FGFR1 receptor complex in the presence of klotho. Activation of the FGF23-FGFR1 pathway leads to inhibition of 25-OH vitamin D activation and degradation of 1, 25 (OH)2 vitamin D. FGFR inhibitors block the catabolism of 1, 25 (OH)2 vitamin D, and sodium-phosphate co-transporters in the proximal renal tubule cell thereby leading to hyperphosphatemia. (C) Pathophysiology of FGFR inhibitor-associated diarrhea: The FGFR4/FGF19/ERK1/2 pathway potentiates the conversion of cholesterol to bile acid in the liver. FGFR inhibitors block the conversion of cholesterol to bile acid thereby leading to altered bile acid metabolism.