The diversity of 2D materials systems has been increasing substantially over the last years, and each new system offers new and exciting research opportunities. While a prime route for increasing complexity is the fabrication of 2D layer vertical heterostructures by stamping, in the present talk in situ fabrication of new 2D materials or of material systems with new functionalities and properties are under concern. A common ingredient of all systems is an epitaxial layer of graphene (Gr).  The material systems highlighted are (i) cluster superlattice membranes, a new freestanding 2D material of interest in nanocatalysis and nanomagnetism; (ii) single crystal Gr on Ir(110), which works well as a nanotemplate for uniaxial alignment of molecular species; (iii) a monolayer of VS2 on Gr/Ir(111), a charge density wave (CDW) system which displays unexpectedly a full CDW gap in the unoccupied states; and lastly (iv) gated transition metal dichalcogenide layers using contactless chemical doping through a Gr substrate.