RASGRP4 and intervertebral disk degenerative disorder: We obtained 20 differentially expressed MAPK‐related genes, of which RASGRP4, DUSP3, HSPA1A, HSPA6, IL1R1, KRAS, MAP3K5, RPS6KA1, BRAF, TNF, CACNA1I, and RPS6KA5 were overexpressed in IDD samples, whereas RASGRP1, DUSP14, DUSP2, RRAS2, JUN, PRKACB, RAP1A, and RAP1B were downregulated (Figure 2A,B).