This study investigates the role of small RNAs (sRNAs) from the fungal pathogen *Botrytis cinerea* in suppressing plant immunity. The researchers identified 73 Bc-sRNAs that target host genes in *Arabidopsis thaliana* and *Solanum lycopersicum* (tomato). These sRNAs hijack the host's RNA interference (RNAi) machinery by binding to Arabidopsis Argonaute 1 (AGO1) and silencing host genes involved in immunity, such as mitogen-activated protein kinases (MAPKs) and cell wall-associated kinases (WAKs). The Arabidopsis ago1 mutant and the *B. cinerea* dicer-like 1 and 2 (dcl1 dcl2) double mutant showed reduced susceptibility to *B. cinerea*, indicating that these sRNAs are essential for the pathogen's virulence. The study demonstrates that fungal sRNAs can act as effectors to suppress plant immunity, providing a novel mechanism for pathogen virulence.This study investigates the role of small RNAs (sRNAs) from the fungal pathogen *Botrytis cinerea* in suppressing plant immunity. The researchers identified 73 Bc-sRNAs that target host genes in *Arabidopsis thaliana* and *Solanum lycopersicum* (tomato). These sRNAs hijack the host's RNA interference (RNAi) machinery by binding to Arabidopsis Argonaute 1 (AGO1) and silencing host genes involved in immunity, such as mitogen-activated protein kinases (MAPKs) and cell wall-associated kinases (WAKs). The Arabidopsis ago1 mutant and the *B. cinerea* dicer-like 1 and 2 (dcl1 dcl2) double mutant showed reduced susceptibility to *B. cinerea*, indicating that these sRNAs are essential for the pathogen's virulence. The study demonstrates that fungal sRNAs can act as effectors to suppress plant immunity, providing a novel mechanism for pathogen virulence.