POU5F1 and germ cell tumor: Nevertheless, a mechanism of CDDP resistance in this cell line, achieved by cultivation in differentiation-inducing medium leading to the loss of POU5F1 expression [34], parallels at the molecular level the one induced directly by CDDP treatment, as demonstrated by the fact that CDDP induces resistance to itself by triggering a differentiation response via decrease in the expression of POU5F1 in pluripotent germ cell tumor (GCT) cells [47].