diff --git a/content/3.defense-systems/thoeris.md b/content/3.defense-systems/thoeris.md
index a7511d05d2e75874b6b2c2cc4f4eb1dc784f6469..43e92a2943312f922a8b67222e0369d1c7475a65 100644
--- a/content/3.defense-systems/thoeris.md
+++ b/content/3.defense-systems/thoeris.md
@@ -21,18 +21,17 @@ relevantAbstracts:
 # Thoeris
 
 ## Description
-Thoeris is a two-gene defense system identified in more than 2000 bacterial genomes. It consists of the genes thsA and thsB. Its anti-phage function was experimentally validated in _Bacillus subtilis_. In response to phage infection, it produces an isomer of cyclic ADP-ribose, which leads to  depletion of NAD+ and results in abortive infection.
+Thoeris is a two-gene defense system identified in more than 2000 bacterial genomes. It consists of the genes ThsA and thsB. Its anti-phage function was experimentally validated in *Bacillus subtilis* :ref{doi=10.1126/science.aar4120}. In response to phage infection, it produces an isomer of cyclic ADP-ribose, which leads to  depletion of NAD+ and results in abortive infection.
 
-ThsA contains the sirtuin-like domain which binds to nicotinamide adenine dinucleotide (NAD) metabolites. The N112A point mutation neutralizes the Thoeris defense system and abolishes the NAD+ hydrolase activity of thsA. It lacks a N-terminal transmembrane domain, and is predicted to be cytoplasmic. 
-
-ThsB is proposed to participate in the recognition of phage infection, as various thsB proteins sense different phage components.ThsB is found in more than 50% of Thoeris systems in multiple diverse copies.
+ThsA contains the sirtuin-like domain which binds to nicotinamide adenine dinucleotide (NAD) metabolites. The N112A point mutation neutralizes the Thoeris defense system and abolishes the NAD+ hydrolase activity of thsA :ref{doi=10.1126/science.aar4120}. It lacks a N-terminal transmembrane domain, and is predicted to be cytoplasmic. 
 
+ThsB contains a TIR domain :ref{doi=10.1126/science.aar4120} is proposed to participate in the recognition of phage infection, as various thsB proteins sense different phage components.ThsB is found in more than 50% of Thoeris systems in multiple diverse copies :ref{doi=10.1126/science.aar4120}.
 
 ## Molecular mechanism
 
-The Thoeris system is believed to function by degrading NAD+ (a cofactor of central metabolism) to stop the growth of phage-infected cells and prevent the transmission of the phage to neighboring bacteria.
+The Thoeris system functions by degrading NAD+ (a cofactor of central metabolism) to stop the growth of phage-infected cells and prevent the transmission of the phage to neighboring bacteria :ref{doi=10.1038/s41467-020-16703-w}.
 
-The protein ThsB, featuring the TIR domain, plays a cruial role in identifying phage invasion. Upon detecting the infection, the TIR domain becomes enzymatically active, initiating the synthesis of a cADPR isomer molecule. This molecule acts as a signal, binding to the ThsA effector, likely through its C-terminal SLOG domain, thereby activating its NADase activity. Consequently, the NADase effector reduces NAD+ cellular levels, creating an environment unsuitable for phage replication.
+The protein ThsB, featuring the TIR domain, plays a cruial role in identifying phage invasion. Upon detecting the infection, the TIR domain becomes enzymatically active, initiating the synthesis of a cADPR isomer molecule :ref{doi=10.1038/s41586-021-04098-7}. This molecule acts as a signal, binding to the ThsA effector, likely through its C-terminal SLOG domain, thereby activating its NADase activity :ref{doi=10.1038/s41586-021-04098-7}. Consequently, the NADase effector reduces NAD+ cellular levels, creating an environment unsuitable for phage replication :ref{doi=10.1038/s41586-021-04098-7,10.1038/s41467-020-16703-w}.
 
 ## Example of genomic structure