Exposure of TMZ-resistant GBM cells to 10 μM curcumin increased apoptosis two-fold (from 4% to 8%), with a resulting decrease in Cx43 expression by 40%; subsequent exposure to MG132 negated Cx43 degradation, implicating the ubiquitin–proteasome pathway in Cx43 degradation [39]. The gene discussed is GJA1; the disease is glioblastoma.