  We report on the current status of our search for protoclusters around
quasars at z > 4. While the search is still very incomplete, clustered
companion galaxies are found in virtually every case examined so far. The
implied comoving number densities of protogalaxies are two to four orders of
magnitude higher than expected for the general field, but are comparable to the
number densities in rich cluster cores. The comoving densities of star
formation in these regions are also enhanced by a comparable factor. We
interpret these results as an evidence for biased galaxy formation in the
highest peaks of the primordial density field.
