Extended Data Fig. 1: Window implantation after tumour growth causes artificial compression.

a, Methodology and timeline for tumour induction. The outlined image was taken using a fluorescent stereomicroscope. b, After showing that window implantation after tumour formation applies artificial compression, which relaxes over 6 days, we switched to window implantation before the tumour induction. Window implantation before tumour induction does not alter the solid-stress level (Fig. 2h). The XZ and XY views of the bead (E = 1.3 ± 0.13 kPa) in the tumour at days 0, 3, and 6, captured with OCT. c, Aspect ratios of polyacrylamide beads over time (mean ± STD, n = 3–6 beads).