The notion of exploiting the regenerative potential of the human brain in physiological aging or neurological diseases represents a particularly attractive alternative to conventional strategies for enhancing or restoring brain function. However, a major first question to address is whether the human brain does possess the ability to regenerate. The existence of human adult hippocampal neurogenesis (AHN) has been at the center of a fierce scientific debate for many years. The advent of single-cell transcriptomic technologies was initially viewed as a panacea to resolving this controversy. However, recent single-cell RNA sequencing studies in the human hippocampus yielded conflicting results. Here, we critically discuss and re-analyze previously published AHN-related single-cell transcriptomic datasets. We argue that, although promising, the single-cell transcriptomic profiling of AHN in the human brain can be confounded by methodological, conceptual, and biological factors that need to be consistently addressed across studies and openly discussed within the scientific community. • Single-cell profiling of adult hippocampal neurogenesis can offer key insights • Methodological and conceptual confounders can impact the resulting datasets • Sample size and stratification, data processing, and marker selection are critical • Efforts should focus on optimization and public sharing of protocols and pipelines Tosoni et al. probe the challenges related to the design, analysis, and interpretation of single-cell transcriptomic studies in the adult human hippocampal neurogenic niche and propose a series of critical points of attention via re-analysis and meta-analysis of previously published datasets. [ABSTRACT FROM AUTHOR]