Dairkee et al. [63] found that, unlike cultured breast adenocarcinoma cell lines (T47D, SKBR3, BT20, etc.), primary tumor cell cultures exhibited a characteristic “limited proliferation” phenotype, including overexpression of genes associated with the transforming growth factor-β (TGF-β) signaling pathway, such as lysyl oxidase-like 1 (LOXL1), Runt-related transcription factor 1 (RUNX1), and death-associated protein kinase 1 (DAPK1), etc. At the core of this profile was a noticeable absence of hTERT expression and telomerase activity. The gene discussed is RUNX1; the disease is breast adenocarcinoma.