We observed the activation of caspase 3 in both the colon cancer cell lines that were investigated after 24 h of treatment with the SeNps (Figure 2b,c and Figure 3c,d), as well as the cleavage of PARP1 to its characteristic 89 kDa fragment, which is associated with apoptosis in HT29 cells (Figure 2d). This evidence concerns the gene CASP3 and malignant colon neoplasm.