The Nizari are the biggest group of Shiite Ismailites. They emphasize social justice, pluralism and human reason in the framework of Islam. They are the second-largest group of Shiites. There are about 15-20 million, spread over many countries; in Pakistan up to 75% of the people may follow this faith. Nizari still have an imam that is descended from Ali, the current imam is Karim Aga Khan IV.