The inner membrane of the nuclear envelope is connected to the outer nuclear envelope membrane through nuclear pores. It contains a number of proteins involved in the structural organization of the nucleus and the attachment of chromatin to the nuclear envelope. In metazoan cells, the inner nuclear membrane contains proteins of the nuclear lamina, a protein meshwork underlying the nuclear envelope and providing structural support. Mutations in inner nuclear envelope proteins can cause nuclear envelopathies, a number of genetic disorders in humans.
It has saved millions of people from malaria over the decades, but it was useless against bacteria because it didn't have a way to penetrate the membrane that surrounds bacterial cells ... membrane.