Dupuytren’s and Peyronie’s disease are believed to be related, to share a common genetic starting point. This has been an assumption, not hard fact: the genetic starting points of these conditions are not yet known, much less known to be the same. Doctors have been wrong on these issues in the past: in the 1800’s, it was an accepted “fact” that Dupuytren’s and gout were related. They are not: the only relationship is demographic overlap. We now have better tools to find genetic similarities of Dupuytren’s Disease (DD) and Peyronie’s Disease (PD). All normal body processes are regulated and balanced by genetically controlled feedback loops: genes are upregulated (turned on) or downregulated (turned off) to maintain balance. DD and PD are the end effects of a broken feedback loop: an on switch is stuck in the on position, an off switch is stuck off, or both. One way to study up and down regulation is to use reverse transcriptase. Here’s how it works. Genes are different molecules strung together into huge DNA molecules. When a gene is upregulated (turned on), it makes RNA molecules, which are like small, mirror images of itself. RNA carries orders from the boss DNA to control the rest of the cell. Reverse transcriptase is a laboratory technique which reverses this process, making DNA mirror images of RNA taken from living cells to find what genes the RNA came from – what genes are upregulated. In this study “Comparison of gene expression profiles between Peyronie’s disease and Dupuytren’s contracture” (full text: https://dupuytrens.org/DupPDFs/2004_Qian_1570.pdf), this technique was used to identify upregulated and downregulated genes in Peyronie’s, Dupuytren’s and normal tissues. The result? Yes, DD and PD appear to be genetically related. The list of identified genes and their actions is reviewed in the article. More pieces of the puzzle, more steps closer to a cure.