In honour of Siblings Day 2018, here are 14 sister brands you didn't know were related., we're revealing which brands are actually kinfolk, related by their parent company. Sure, everybody knows Gap, Banana Republic, and Old Navy are in the same family, and that H&M and COS share DNA. But, for example: Did you know about Uniqlo and Theory, too? Click through the slideshow ahead to discover which of your favourite luxury designers and fast-fashion retailers are closer linked than you think.