In the same study, Järvinen et al (2000) observed an increased sensitivity to doxorubicin in a breast cancer cell line (UACC-812) with TOP2α gene amplification and consequent protein overexpression and conversely, a decreased sensitivity to doxorubicin in a breast cancer cell line with TOP2α deletion and concomitantly reduced protein content (MDA-361). Here, TOP2A is linked to breast cancer.