I will describe a holographic approach to QCD where conformal symmetry is broken explicitly in the UV by a relevant operator O. This operator maps to a five dimensional scalar field, the dilaton, with a massive term. Implementing also the IR constraint found by Gursoy, Kiritsis and Nitti, an approximate linear glueball spectrum is obtained which is consistent with lattice data. Finally, I will describe the evolution of the model parameters with the conformal dimension of O. This will suggest a map between the QCD anomaly and the trace anomaly of deformed Conformal Field Theories.