Further examination of the genes that were lower than expected revealed six FGFRi-MEKi DEGs associated with stem cell differentiation, cell self-renewal, cancer, cell proliferation and survival and germ cell tumours, including Etv1 and Etv4 [45–48], Pdk1 [49], Ret [50, 51], Tdgf1 [52] and Calcoco2 [53]. This evidence concerns the gene PDK1 and germ cell tumor.