Fig. 1

Historical reconstruction of the distribution process of the human microglial clone 3 cell line. The human microglial clone 3 cell line was developed in the laboratory of Prof. M Tardieu, Paris, in 1995 (red circle). As shown in the picture, clone 3 has been distributed worldwide, with the acronym of CHME3 cells (blue boxes) or HMC3 cells (green boxes). Distribution followed two main pathways, either directly from Prof. Tardieu’s laboratory (black thick arrows) or indirectly by the first recipient laboratory (black dotted arrows). A second main distributor of the CHME3 cell line is the laboratory of Prof. A Basu, National Brain Research Centre (NBRC), India (purple circle). Since 2014, this laboratory appears to be the main distributor of the CHME3 cells in India. However, we could not trace on the timeline when the cell line was transferred from the laboratory of Prof. Tardieu to NBRC. In addition, we identified several studies (not reported in the schematic), in which the CHME3 cells were used without any indication of the source, and one study in which the cell line was provided by an Academic institution without any link to published data. In 2016, the HMC3 cells were transferred to ATCC®, USA (orange box) and authenticated and distributed under the catalog designation of HMC3 (ATCC®CRL-3304)