Background: Immunodeficiency diseases (IDDs) are associated with an increased proportion of cancer-related morbidity. However, the relationship between IDDs and malignancy readmissions has not been well described. Understanding this relationship could help us to develop a more reasonable discharge plan in the special tumor population. Methods: Using the Nationwide Readmissions Database, we established a retrospective cohort study that included patients with the 16 most common malignancies, and we defined two groups: non-immunodeficiency diseases (NOIDDs) and IDDs. Results: To identify whether the presence or absence of IDDs was associated with readmission, we identified 603,831 patients with malignancies at their time of readmission in which 0.8% had IDDs and in which readmission occurred in 47.3%. Compared with NOIDDs, patients with IDDs had a higher risk of 30-day (hazard ratio (HR) of 1.32; 95% CI of 1.25–1.40), 90-day (HR of 1.27; 95% CI of 1.21–1.34) and 180-day readmission (HR of 1.28; 95% CI of 1.22–1.35). More than one third (37.9%) of patients with IDDs had readmissions that occurred within 30 days and most (82.4%) of them were UPRs. An IDD was an independent risk factor for readmission in patients with colorectal cancer (HR of 1.32; 95% CI of 1.01–1.72), lung cancer (HR of 1.23; 95% CI of 1.02–1.48), non-Hodgkin’s lymphoma (NHL) (HR of 1.16; 95% CI of 1.04–1.28), prostate cancer (HR of 1.45; 95% CI of 1.07–1.96) or stomach cancer (HR of 2.34; 95% CI of 1.33–4.14). Anemia (44.2%), bacterial infections (28.6%) and pneumonia (13.9%) were the 30-day UPR causes in these populations. (4) Conclusions: IDDs were independently associated with higher readmission risks for some malignant tumors. Strategies should be considered to prevent the causes of readmission as a post discharge plan.

Background/Objectives: Tumors are induced by overactivation of oncogenes and loss of tumor suppressor genes. Recently, a family of proteins containing CID (C-terminal domain (CTD)-interacting domain) domains, named CREPT/RPRD1B and p15RS/RPRD1A, has been identified to be involved in tumorigenesis through the regulation of the cell cycle. Interestingly, while p15RS was shown to inhibit cell proliferation, CREPT was demonstrated to promote tumorigenesis by accelerating tumor cell cycle progression. Methods: To decipher why these two proteins function oppositely, we aimed to reveal the disparities in their clinical outcomes and protein properties. Results: We observed that CREPT and p15RS are both highly expressed in tumors, but with opposite prognostic implications. We confirmed that CREPT promotes, but p15RS inhibits cell proliferation via regulation of Wnt/β-catenin signaling activation. The CID domain of CREPT differs from that of p15RS in conformation and charge distribution. CREPT exhibits a significantly stronger oligomerization capacity than p15RS, which is mediated by the CCT (coiled-coil terminus) domain. We demonstrated that the differences in both CID and CCT domains between CREPT and p15RS contribute to their opposite physiological functions. Conclusions: In conclusion, our results demonstrate that despite high primary sequence similarity, CREPT and p15RS exhibit distinctive biochemical properties. These differences ultimately explain their functional divergence in tumorigenesis and offer novel insights into CREPT-targeted drug design.