The CSCLYK-Gen3K dendrons led to levels of inhibition of SKBR3 cell proliferation comparable to that of Herceptin, albeit only at the lowest concentration tested (5 μg/mL), confirming that the CCY domain is not essential in inhibiting the HER2-driven stimulation of proliferation in this type of breast cancer cell [36]. Here, ERBB2 is linked to breast cancer.