PCNA and colorectal cancer: For example, a two‐organ MoC platform modeled the gut and liver in two separate chambers, interconnected by vessel‐like channels, to recapitulate colorectal cancer metastasis to liver tissues.[88] N‐cadherin and proliferating cell nuclear antigen (PCNA) were overexpressed in both gut and liver tissues, indicating metastasis of colorectal cancer cells and colonization at the liver site.