In the presence of the blood-testicular barrier, it is difficult for drugs to enter the testicles, and the effect of chemotherapy is not ideal[29]; at the same time, testicular tumor cells can also express high levels of drug-resistant proteins, such as P-glycoprotein (P-GP) and breast cancer drug-resistant protein (BCRP), which results in chemotherapy resistance.[42] Although orchiectomy alone can sometimes lead to long-term survival, orchiectomy should not be used as the only surgical treatment, even in stage I patients. The gene discussed is ABCG2; the disease is neoplasm of testis.