Seed and Soil: Cancer Metastasis Simulator

This simulation visualizes the seed-and-soil hypothesis of metastasis: circulating tumor cells released from a primary tumor travel a simplified 3D circulatory system and reach several distant organs in rough proportion to each organ's blood-flow share — but only take root and grow into a visible metastatic nodule at organs whose local tissue "soil" is compatible with that cancer type's "seed" profile. Switch between cancer types to see how the same arrival pattern produces very different metastasis patterns, and compare the live per-organ arrival tally against the successful-metastasis tally to see that arrival rate alone does not predict where metastases actually form.