The word, signifier is there that means something is signified.
I'm sure in the virtual kitchen of your mind there are also unicorns and goblins helping with the dishes but it doesn't mean I can ask them to chop my vegetables. Similarly, there is nothing real that distinguishes 'slavs' from 'the rest of the world. Slavic languages share some features as do some people who speak them but there is no slavic race or people these days.
R1a1 Y DNA haplogroup
Sorry, you're saying there's a Slavic gene?