Quantum fluctuations of the string worldsheet lead to important effects in gauge-string duality. One example is the Lüscher term is the QQ-bar potential in QCD, important for matching the lattice data. I will discuss non-conformal holography of the N=2* theory which provides a controllable setup where the effects of string fluctuations are explicitly calculable in field theory, using localization, even though the problem is intrinsically strongly-coupled. The results obtained by direct quantization of the dual string theory perfectly match the field-theory predictions, after subtle effects like dilaton coupling to the string worldsheet are properly taken into account.