Expected hadronic γ-ray spectra from the molecular cloud DR21 considering the two possible CR distributions given by the Kraichnan (thin lines) and Bohm (thick lines) cases. The spectra are calculated considering different relative distances from Cyg OB2: 40 pc (solid line), 60 pc (dashed line), and 80 pc (dot-dashed line). The dotted line shows the CTA North point source sensitivity for 50 h of exposure considering the Alpha Configuration.