HPGDS and neoplasm: In comparison, among the other three top PGD2-abundant cell types, the abundance of PGD2 shows a significant decreasing trend in Fibro cells and pDCs across normal lung, tumor lung, and metastatic brain tissues (Figure 3B), as well as in early and advanced stages (Figure 3C) and at different differentiation levels (well, middle, and poor; Figure 3D).