FGFR4 and cancer: In contrast, cancer-associated FGFR4-R slightly induced MST2 cleavage (Fig. 3c; FGFR4-G/R vary in stability and signal output; endogenous FGFR4 in MDA-MB-453 contains G388R and the activating Y367C alterations [12, 33, 50–52]).