Hierarchical clustering analysis demonstrated that the expression profiles of some MAPK signaling pathway members, such as MAPK1 (Mitogen-Activated Protein Kinase 1), MAPK14 (p38) (Mitogen-Activated Protein Kinase 14), FGF12 (Fibroblast Growth Factor 12), MKNK2 (MAP Kinase Interacting Serine/Threonine Kinase 2), RPS6KA1 (Ribosomal Protein S6 Kinase, 90kDa, Polypeptide 1), FOS (FBJ Murine Osteosarcoma Viral Oncogene Homolog) and RASGRP1-2 (RAS Guanyl Releasing Protein 1–2), enable CCs to be successfully distinguished from MGCs in PCOS. The gene discussed is MKNK2; the disease is polycystic ovary syndrome.