TNF and congenital bilateral aplasia of vas deferens from CFTR mutation: Several factors and signaling pathways have been linked to CAVD, e.g. interleukins, tumor necrosis factor (TNF), matrix metalloproteinases, bone morphogenic protein 2 (BMP2) and osteogenic regulator runt-related transcription factor 2 (RUNX2) [1, 2].