EGFR is the critical signal transducer linking HB‐EGF to MAPK cascades.16 Our previous study showed that HB‐EGF inhibitor CRM197 significantly suppresses the expression of EGFR in ovarian cancer cells.9 To determine whether the EGFR/JNK/p38MAPK pathway was affected by CRM197 treatment in ovarian cancer cells, we examined EGFR expression and JNK/p38MAPK pathway activity in ovarian cancer cells following CRM197 treatment. The gene discussed is MAPK8; the disease is ovarian cancer.