Add to ORKGWe present a lattice study of the zero-temperature line of chiral symmetry breaking phase transitions in the conformal window of QCD for varying number of flavors. We argue that it is consistent with a lower edge of the conformal window between $N_f=8$ and $N_f=6$, and remarkably in agreement with perturbation theory and recent large-$N$ arguments. We add a theoretical analysis of the anomalous dimension of the scalar glueball operator and show that its agreement with perturbation theory and large-$N$ arguments would be sufficient to exclude an ultraviolet-infrared fixed-point merging as a mechanism for the loss of conformality