Bayer PTEFb Compound means any PTEFb inhibiting compound developed within the PTEFb Technology and Controlled by Bayer or any of its Affiliates as of the Effective Date. By way of clarity, the term Bayer PTEFb Compound includes BAY1143572, BAY1251152 and BAY2396217 as well as back-up series and intermediates relating to such compounds, if any, within the PTEFb Platform.