  A large sample of blazar from the Candidate Gamma Ray Blazar Survey (CGRaBS)
has been observed with the Owens Valley Radio Observatory (OVRO) 40-Meter
Telescope at 15GHz. Using these quasi-simultaneous observations, we study the
connection between the gamma-ray behavior of blazars as detected by Fermi-LAT
and the cm band as observed by the F-GAMMA project with the OVRO 40-Meter
Telescope. Comparing the light curves for a large number of sources, it is
possible to study in detail the relation between the gamma-ray and radio
activity of Fermi-LAT detected gamma-ray blazars. We present first results for
correlations between Fermi-LAT and our 15 ~GHz observations.
