BCL2 and Erythema: When Survivin acts on subdermal microvascular endothelial cells, normal physiological apoptotic activity in microvessels in the downstream apoptotic pathway can be suppressed by regulating the expression of apoptotic proteins such as caspase-3 and Bcl-2, and the relative number of microvessels increases, which is an important pathological cause of psoriasis, leading to erythema.