The level of periostin in the nasal secretion of children with hypertrophies (n=9) was 21.6 [10.7; 1516.8] ng/mg, which was significantly higher than that in children with polyposis (n=6): 0.17 [0.001; 0.32] ng/mg; W=48.0; p=0.02 (Figures 1, 2). This evidence concerns the gene POSTN and polyposis.