Further, it elevated the BCl2 family proteins such as Bid, Bax, and Bad, both at RNA and protein levels (Figures 4, 5).To ensure the TPEN created the zinc deficiency in the RD cells, we used zinquin ethyl ester, which binds to the zinc and emits fluorescence upon binding with zinc (Figure 6). This evidence concerns the gene BCL2 and Zinc deficiency.