Given the task definition and input, reply with output. In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

Lorian has also described the formation of numerous aberrant cross - walls by S . faecalis grown in the presence of subinhibitory concentrations of penicillin [ 15 ] .
S . faecalis