<prompt> All are true about levamisole EXCEPT :Act as an immunostimulatorAct as an immunodepressor in high dosesSingle dose is sufficient for the treatment of psoriasisActs as antihelminthic by causing depolarization  <response>: Levamisole is an immunomodulator acting as immunostimulant at low doses and immunodepressant at high doses.It was used as anti-helminthic and causes depolarization by stimulating nicotinic receptors.It is used for the treatment of colorectal carcinoma in combination with 5-FU.It is slow to act in psoriasis and requires two-day therapy per week for prolonged periods. 