Upregulation of PAICS has been reported for lung squamous cell carcinoma [47], and our Oncomine database research yielded several expression studies in various tumor entities (e.g., brain and CNS cancer, bladder cancer, colorectal cancer, head and neck cancer and lung cancer) in which PAICS mRNA was upregulated compared with corresponding normal tissue. Here, PAICS is linked to squamous cell lung carcinoma.