VEGFA and atrial fibrillation: Moreover, gene assay was also performed to detect the different expression of global mRNA among AF-MSCs cultured under hypoxic and normoxic condition (Table 1 and Supplementary Figure S1), which revealed the expression of VEGF was increased in AF-MSCs cultured in hypoxic condition compared to normoxic condition.Next, we investigated whether AF-MSC-hypoCM influences the proliferation of human dermal fibroblasts.