ATF4 and endometrial cancer: We examined the protein expression of key components in PI3K/AKT, GCN2/ATF4, epithelial–mesenchymal transition and apoptosis pathways in ROR1‐positive endometrial cancer cell lines HEC‐1‐B, KLE, ARK1, RL95‐2 and Ishikawa, following treatment with GZD824 for 48 h (Figure 4).