A recent study on the expression status of various ABC transporters in different tumors revealed that, while ABC transporter expression correlated with different stages of breast, kidney or lung tumors, a lower ABCB1 mRNA expression level was predictive of significantly longer survival of patients with ovarian or kidney cancer and thymoma (Kadioglu et al., 2020), supporting the clinical significance of efflux ABC transporters and needs for new means to achieve individualized pharmacotherapy. Here, ABCG2 is linked to thymoma.