Figure shows the CD spectra of COSAN with ctDNA ([ctDNA(pb)]/[COSAN] ratios ranging from 0 to 1.5). Achiral molecules, such as COSAN, lack a CD spectrum, but upon binding to DNA, either through intercalation or minor-groove binding, they are in the chiral environment of DNA and thus acquire an ICD signal. By contrast, in the presence of ctDNA, COSAN lacks an ICD signal. For this reason, we rejected the second hypothesis.