To exclude the impact of venetoclax itself on the bleaching pathway or its toxicity, we exposed 6 PC and 6 NPC coral fragments to venetoclax at ambient temperature and compared it to PC and NPC corals treated with DMSO (control), which was used as the solvent for venetoclax. Corals in control treatment showed no signs of bleaching, apparent tissue loss or polyp bailout, that accompany high toxicity. Confocal microscopy analysis confirmed that in control treatment, corals do not show any signs of bleaching (p(ctrl 0 – ctrl 5) = 0.9737), and corals treated by venetoclax at ambient temperature even showed an increase in symbiont:host signal ratio (p(ven+AT 0 – ven+AT 5) <0.001) (Fig. 4A).