The gene encoding a matrix metalloprotease (MMP1) as well as genes involved in the control of apoptosis, such as FAS, CASP1, or TNFSF10 (TRAIL) were also upregulated, whereas OCLN, encoding occludin, a key protein regulating tight junctions, was downregulated by ZIKV AF (Fig. 3a and b). This evidence concerns the gene MMP1 and atrial fibrillation.