PTGDS and neoplasm: As AA metabolites play integral roles in tumour immunity, especially in the heterotypic interactions between tumour and immune cells in the TIME,31 we audited the metabolome of PIK3CAmut cells and found that the levels of 15 common AA pathway‐related metabolites in cell lysates, including LTB4, PGA2, PGE2, PGD2, 5‐HETE, 12‐HETE and 15‐HETE, increased dramatically, among which LTB4 was one of the most significantly upregulated metabolites (Figure 6A).