Figure 4. Validation of hub genes expression in external datasets. (A–D) The expression of MNDA, TNC, CHIT1, and MMP9 in GSE44000 dataset ((A) P < 0.05, (B) P < 0.01, (C) P < 0.05, (D) P < 0.01). (E–M) The expression of MMP9, MNDA, TNC, CHI3L1, CHIT1, COL11A1, COMP, CXCL8, and DCSTAMP in GSE3467 dataset ((E) P < 0.05, (F) P < 0.01, (G) P < 0.001, (H) P < 0.001, (I) P < 0.01, (J) P < 0.05, (K) P < 0.001, (L) P < 0.05, (M) P < 0.001). P < 0.001 was denoted as “***”, P < 0.01 as “**”, P < 0.05 as “*”, and P > 0.05 as “ns”.