a, Engraftment is equivalent in Nlgn3 knockout and wild-type mice. In vivo bioluminescence imaging of SU-pcGBM2 xenografts 2 weeks after xenograft in WT;NSG (WT; left) or Nlgn3 KO;NSG mice (KO; right). The heat map superimposed over the mouse heads represents the degree of photon emission by cells expressing firefly luciferase. b, Absolute flux of pHGG cells in identically manipulated WT;NSG (n = 11) and Nlgn3 KO;NSG (n = 14) mice, measured by IVIS imaging 2 weeks after xenograft illustrates no significant difference (P > 0.05) in tumour engraftment (two-sided Mann–Whitney test). Data are mean ± s.e.m. c, d, Data from Fig. 1 shown on the same axis (c) and with each independent cohort colour-coded for comparison of littermates (d). Data illustrate growth of pHGG (SU-pcGBM2) xenografts in identically manipulated WT;NSG (black dots, n = 11) and Nlgn3y/−;NSG (grey dots, n = 14) mice, measured by IVIS imaging (fold change in total photon flux) and shown at 6, 12, 18 and 24 weeks post-xenograft. Data were replicated in five independent cohorts (litters) of mice xenografted with different cell preparations on different days and the data from these five biological replicates are shown combined with each cohort colour-coded (that is, littermates are shown in the same colour). **P < 0.01, ****P < 0.0001, two-sided Mann–Whitney test. Data are mean ± s.e.m.