Sourced Friedmann equations with holographic energy density

We reexamine cosmological applications of the holographic energy density in the framework of sourced Friedmann equations. This is considered as a general framework because it can accommodate an interaction between holographic and ordinary matter naturally. In the case that the IR cutoff is taken to be the Hubble horizon, it is shown that the equations of state for the holographic energy density is not fixed as $\omega_{\rm \Lambda}=0$ but it is indeterminate. Consequently, the view of the holographic energy density as a dynamical cosmological constant is still problematic. Finally we discuss a possibility of the holographic energy density being the cosmological constant with $\omega_{\rm \Lambda}=-1$.