diff --git a/src/repertoire.r b/src/repertoire.r
index b7a5d83..fda052a 100644
--- a/src/repertoire.r
+++ b/src/repertoire.r
@@ -2,13 +2,6 @@ library(immuneSIM)
 library(Biostrings)
 
 generate_repertoires <- function(number_of_sequences) {
-  a_chain <- immuneSIM(
-    number_of_seqs = number_of_sequences,
-    species = "hs",
-    receptor = "tr",
-    chain = "a",
-    verbose = TRUE
-  )
   b_chain <- immuneSIM(
     number_of_seqs = number_of_sequences,
     species = "hs",
@@ -16,7 +9,7 @@ generate_repertoires <- function(number_of_sequences) {
     chain = "b",
     verbose = TRUE
   )
-  return(list("a_chain" = a_chain, "b_chain" = b_chain))
+  return(b_chain)
 }
 
 process_chain <- function(repertoire) {