Three-dimensional radial distribution of the member galaxies in all MAMBO (top), GAEA-H (middle), and GAEA-F (bottom) proto-clusters (z = 1.5 − 4). The radius is in units of the estimated proto-cluster radius, r_pc. The red lines show the numbers and densities of the proto-cluster members, and the blue lines those of the non-member galaxies. The solid lines show the galaxy number in the shells (left Y-axis), while the dotted lines show the galaxy density in the shells (right Y-axis).