Caspase-3是执行凋亡效应的caspase酶家族的一员，可以同时激活凋亡的内源性途径和外源性途径，被作为早期凋亡的特征性信号。 TUNEL可作为细胞晚期凋亡的组织学检测方法。

图A展示了ONC后7天有无应用DFO对视网膜表达Cleaved caspase-3的影响，结果证明均无影响。ONC后7d视网膜与假手术组一样，均无Cleaved caspase-3阳性表达，并且应用DFO抑制RGCs铁死亡不能诱导其发生凋亡。图4B所示，ONC后直到14天，GCL出现少量的TUNEL阳性信号，表明细胞凋亡不是TON诱导RGCs死亡的主要途径。

Caspase-3 is a member of the caspase enzyme family that performs apoptotic effects. It can activate both the endogenous and exogenous pathways of apoptosis and is used as a characteristic signal of early apoptosis. TUNEL can be used as a histological detection method for late cell apoptosis.

Figure A shows the effect of DFO on the expression of Cleaved caspase-3 in the retina 7 days after ONC, and the results prove that there is no effect. Like the sham operation group, the retina on the 7th day after ONC had no positive expression of Cleaved caspase-3, and the application of DFO to inhibit the iron death of RGCs could not induce their apoptosis. As shown in Figure 4B, up to 14 days after ONC, a small amount of TUNEL positive signal appeared in GCL, indicating that apoptosis is not the main way for TON to induce the death of RGCs.