while the α-type psms are regarded as major cytolysins, the β-type psms are though to play a role in biofilm formation. "s. epidermidis", which is a known opportunistic pathogen, has a high level of β-type psm expression. in addition "in vitro" measurement of psmβ expression in "s. epidermidis" has shown to be increased in biofilm as opposed to planktonic growth, further suggesting a link between psmβ and biofilm formation. altering the structure of psmβ has been demonstrated to disrupt their ability to influence biofilm formation.