BCL2 and neoplasm: Interestingly, most of these studies support the activation of apoptosis in tumour cells by promoting the upregulation of pro-apoptotic BAX and Bak and the downregulation of anti-apoptotic bcl-2 and bcl-xL. Furthermore, sulforaphane-coated selenium and tellurium nanoparticles appear to specifically target tumour cells, whereas normal cells, MCF-10A, have a better tolerance to treatment, as observed in the MTT assay [61,66,67].