Polycomb repressive complexes 1 and 2 both regulate maintenance of X inactivation in extra-embryonic lineages of post-implantation embryos by affecting overlapping yet different genes, thus implying potentially independent roles for the two complexes.

Stewart-Morgan et al. present isolation of DNA by 5-ethynyl-deoxyuridine labelling for mass spectrometry, a highly sensitive, quantitative mass spectrometry-based method for measuring DNA modifications on metabolically labelled DNA. They apply it to study DNA methylation and hydroxymethylation propagation.

With whole-genome screens using a bivalent MHC class I gene expression readout, Sparbier et al. identify opposing roles for Menin and KMT2A/B in modulating activating H3K4me3 versus repressive H3K27me3 at bivalent promoters to regulate gene activation.

Jung-Garcia et al. dissect the contributions of isoforms of the inner nuclear membrane protein LAP1 to nuclear envelope blebbing, constrained migration and invasion in melanoma cells.

Wong et al. report that expanding human embryonic stem cell-derived endodermal progenitors serve as a ventral foregut model, through which they identify a link between progenitor expansion and tissue-specific changes in the enhancer landscape.

Adriaenssens et al. provide evidence suggesting that cytosolic small heat shock proteins localize to the mitochondrial intermembrane space, where they operate as molecular chaperones.

Independent but complementary studies from Vakoc and Stegmaier identify and characterize a role for ETV6 in counteracting the transcriptional activity of EWS–FLI during Ewing sarcoma development, which may be targeted for therapeutic benefits.

Deshwal et al. show that the protease PARL regulates coenzyme Q (CoQ) via the lipid transfer protein STARD7. Mitochondrial STARD7 ensures CoQ synthesis; cytosolic STARD7 preserves CoQ transport to the membrane, protecting cells against ferroptosis.

Independent but complementary studies from Vakoc and Stegmaier identify and characterize a role for ETV6 in counteracting the transcriptional activity of EWS-FLI1 during Ewing sarcoma development, which may be targeted for therapeutic benefits.

Mitchell et al. identify reduced osteoprogenitors and increased mesenchymal stromal cells in old bone marrow niche, which creates an IL1-mediated inflammatory milieu that skews myeloid differentiation and impairs haematopoietic regeneration.

Kara McKinley is an assistant professor of stem-cell and regenerative biology at Harvard University. In addition to advancing our understanding of endometrial regeneration, she has tackled the gender bias in the academic job market by founding the ‘Leading Edge Fellows’ program. Nature Cell Biology contacted her to discuss her career and goals for our research community.

The Institute of Molecular and Cell Biology (IMCB) in Singapore has helped the local scientific community to grow. Nature Cell Biology spoke to Wanjin Hong (executive director at A*STAR’s IMCB) and Guillaume Thibault (associate professor affiliated with Nanyang Technological University Singapore, National University of Singapore and A*STAR’s IMCB), who have dedicated parts of their careers to the growth of cell biology research in Singapore, about the history and directions of cell biological research programs in Singapore.

Alternative splicing of eukaryotic messenger RNA transcripts often leads to the production of several mature RNAs — including linear RNAs and circular RNAs (circRNAs) — from a single gene locus. The names given to circRNAs are often ambiguous and lack consistency across studies. This Comment calls on the community to embrace a common nomenclature for naming circRNAs to ensure clarity and reproducibility.