Proliferation but not apoptosis changes as a function of tissue microenvironment. (a–c) Images of TC71-GFP cells xenografted in zebrafish larvae at 2 dpf and imaged in their respective seeding sites (CHT, PVS, HBV) 3 and 7 dpf. Graphs indicate change in area over 4 d. Note that individual paired measurements within each tissue microenvironment suggest that fold growth change is not influenced by initial seeding cluster size. (d) Fold growth as measured by change in measured area of CHT (a), PVS (b) , or HBV (c) over a period of 4 d. PVS shows a larger increase in fold growth compared to HBV. (e) Relative size of TC71 clusters varies greatly as a function of tissue microenvironment, which is likely a result of differential seeding rates during xenografts. (f) XY plot of cluster size (cell count) vs. proportion of PH3 positive cells (see Fig. 3). Proliferation rate does not seem to correlate to size of clusters, suggesting this difference does not greatly impact the functional state of cells. Asterisks mark significant differences (Dunn’s multiple comparison test, P < 0.05). Scale bars, 20 µm.