In conclusion, bortezomib is a potential drug for induction of apoptosis and anti-proliferation in GIST cells with resistance to imatinib, including resistance via acquisition of secondary KIT mutations (Bauer et al., 2010; Rausch et al., 2020) and loss of oncogenic KIT proteins with cyclin D1 overexpression. The gene discussed is CCND1; the disease is gastrointestinal stromal tumor.