As shown in Fig. 2A, GDF15 (P = 1.62E‐12), GDF11 (P = 1.38E‐2), GDF9 (P = 7.2811E‐3), and GDF3 (P = 4.95E‐6) were significantly up-regulated in primary tumor tissue (n = 415) compared with that in normal tissue (n = 34). This evidence concerns the gene GDF9 and neoplasm.