New ancient genetics work from David Reich et al strongly suggests that the Anatolian languages - of which Hittite is the most attested and this new language Kalasmaic is also a member - are not Indo-European.

Instead, Anatolian is a closely related sibling-branch of IE, both having stemmed from something that would be called Proto-Indo-Anatolian. The Yamnaya forked off to give rise to the Indo-European languages, but were not ancestral to the speakers of Hittite, Luwian, Lydian, Kalasmaian and other Anatolian languages which were previously thought to be a branch of IE.