ERBB2 and breast cancer: Pickl and Ries (2009) demonstrated drug resistance in HER2-positive breast cancer by mimicking the homodimerization of HER2, and Doublier et al. (2012) identified the mechanism of doxorubicin resistance in breast cancer by using MCF7 spheroids. The suitability of Regorafenib as an adjuvant chemotherapy agent for colon cancer was also discovered by using multicellular spheroids of colon cancer HCT116 cells (Yoshii et al., 2016). Spheroids can also be employed for genetic screening, as demonstrated by Schlabach et al. (2008).