The PDAC cells were divided into three states according to CA2 and CD44 expression levels: “State 1” as CA2(-)CD44(+) CICs, “State 2” as CA2(+)CD44(-) differentiated ductal-like cancer cells, and “State 3” as CD44/CA2-negative cells (Figures 4A and 4B). Here, CD44 is linked to cancer.