https://medicalxpress.com/news/2023-09-cell-therapy-death-covid-.html
This article has been published in several media outlets in the last 24 hours. The study it refers to was published in a scientific journal three months ago, but to the best of my recollection (and after searching), it has not been posted here before:
https://www.frontiersin.org/articles/10.3389/fimmu.2023.1200180/full