Blazars display variable emission across the entire electromagnetic spectrum, ranging in time from minutes to years. This variability is generally interpreted as stochastic and unpredictable processes. However, recent studies have inferred the presence of periodic signals coming from blazars. These could be caused by, e.g., a helical jet or a precessing jet due to the presence of a supermassive black hole binary. In this work, we will report on the largest systematic search of periodic emission in the gamma-ray lightcurves of 350 blazars. Using 12 years of Fermi-LAT data, we have built a sample of 24 blazars displaying evidence of periodic emissions. These results will be interpreted in the modeling framework of supermassive black hole binaries.