CDKN1A and cancer: Although the mutational burden is lower than that of other types of cancer, Heitzer and colleagues, using a cancer hot spot panel, identified TP53 mutations in 44% of MFS patients; in addition, variants in other genes, including CDKN1A, FGFR3, PTEN, and RB1, were observed, although at low frequency (i.e., 1%) (32).