Another method for quantifying risk of ovarian cancer is the Risk of Ovarian Cancer Algorithm (ROCA), observes levels over time and determines if they are increasing rapidly enough to warrant transvaginal ultrasound. The Risk of Ovarian Malignancy algorithm uses CA-125 levels and HE4 levels to calculate the risk of ovarian cancer; it may be more effective than RMI. The IOTA models can be used to estimate the probability that an adnexal tumor is malignant. They include LR2 risk model, The Simple Rules risk (SRrisk) calculation and Assessment of Different Neoplasias in the Adnexa (ADNEX) model that can be used to assess risk of malignancy in an adnexal mass, based on its characteristics and risk factors. The QCancer (Ovary) algorithm is used to predict likelihood of ovarian cancer from risk factors.