Good god the misinformation on "tren cough" is retarded. Anyone can get it. Nobody is immune, you're not getting the cough because you're not accidentally injecting in or through a vein. When any oil based injectable inters the bloodstream too quickly, the body seeks to purge said intruders of the bloodstream. The quickest way out is through the lungs.
Stick a needle right in a vein and push in some damn corn oil, you will cough. It is not exclusive to tren. I've only ever nicked a vein an accidentally put in oil once, and that was with test e. Had me rolling on the floor coughing for a good 90 seconds.