DNA methylation is critical for the normal development and functioning of the human brain, such as the proliferation and differentiation of neural stem cells, synaptic plasticity, neuronal reparation, learning, and memory. Despite the physical stability of DNA and methylated DNA compared to other epigenetic modifications, some DNA methylation-based biomarkers have translated into clinical practice. Increasing reports indicate a strong association between DNA methylation profiles and various clinical outcomes in neurological diseases, making DNA methylation profiles valuable as novel clinical markers. In this review, we aim to discuss the latest evidence concerning DNA methylation alterations in the development of neurodegenerative, neurodevelopmental, and neuropsychiatric diseases. We also highlighted the relationship of DNA methylation alterations with the disease progression and outcome in many neurological diseases such as Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, and autism.

Background: Albumin and the albumin-to-globulin ratio (AGR) are established prognostic markers in multiple myeloma (MM); however, the prognostic value of baseline serum total protein in patients with MM undergoing autologous stem cell transplantation (ASCT) remains unclear. Objectives: This study investigated the prognostic significance of baseline total protein for progression-free survival (PFS) in patients with MM undergoing autologous stem cell transplantation (ASCT). Methods: Twenty-one consecutive patients with MM who underwent ASCT between 2023 and 2025 at the Stem Cell Transplant Research Center of Taleghani Hospital were included. Survival outcomes were evaluated using Kaplan-Meier estimates stratified by baseline total protein levels and Cox proportional hazards models. Patients were followed for a median of 19 months (range, 10.5 - 32 months). Results: Higher baseline total protein was significantly associated with inferior PFS (HR, 2.10; 95% CI, 1.08 - 4.08; P = 0.028). Patients with total protein > 9 g/dL had significantly shorter PFS and 12-month PFS than those with total protein ≤ 9 g/dL (log-rank test; P = 0.008 and P = 0.029, respectively). A trend toward inferior OS was observed (log-rank test; P = 0.052). Elevated total protein was strongly correlated with M-protein and globulin levels and was associated with lower hemoglobin levels and a higher erythrocyte sedimentation rate (ESR). Conclusions: Higher baseline total protein is associated with inferior PFS in patients with MM undergoing ASCT. Given its simplicity and universal availability, it may serve as a cost-effective and accessible prognostic marker at the time of diagnosis. Larger prospective studies are needed to validate its independent prognostic value.