ALK and anaplastic large cell lymphoma: To investigate the clinical association of PTGDS in PTCL patients, we performed further analysis and found that the high expression of PTGDS in tumor tissue was statistically correlated with ALK+ ALCL (p = 0.008) and elevated ESR (p = 0.004) in PTCL patients (Fig. 1e, Supplementary Fig. S1E).