PPP1R1B and carcinoma of esophagus: DARPP‐32 and t‐DARPP expression, including DARPP‐32 to t‐DARPP expression ratios, have been linked with patient survival in a number of tumour types, including breast, non‐small cell lung, gastric colorectal and oesophageal cancers.4, 5, 6, 7, 8, 9