PA diagnosis was made for cases presenting as either a low-grade piloid astrocytic neoplasm with solitary MAPK alteration and without 1p deletion (13/15 cases), or with a DNA methylation profile clustering with PA on t-SNE analysis despite a low calibrated score (as defined as < 0.9 in Capper et al. [7]) for PA methylation class (MC) (2 infantile cases with FGFR1 without 1p deletion). This evidence concerns the gene FGFR1 and astrocytic tumor.