Negative regulator of epidermal growth factor receptor (EGFR) signaling. Expressed in vulval precursor cells (VPCs). Highly expressed in all 6 vulval precursor cells (VPCs). At the time of inductive signaling, expression forms a gradient in response to inductive signal: expression is low in P6.p, intermediate in P5.p and P7.p and undiminished in P3.p, P4.p, and P8.p. Later, expression becomes strong again in P5.p and P7.p. Causes ectopic vulval induction. Belongs to the lst-2 family.