Indeed, our results show that (i) CD39 is expressed poorly or not at all in our panel of four CRC cell lines (Tables S1–S4); (ii) ATP and its non-hydrolysable analog ATPγS show similar activities in 2D cell viability assays (Figure 3A, Figure 6E and Figure S2); and (iii) adenosine exposure does not induce any form of cellular death when used at the same concentration as ATP (Figure 4A and Figure 6E). The gene discussed is ENTPD1; the disease is colorectal carcinoma.