Involved in plant defense. Confers resistance to the fungal pathogen C.fulvum through recognition of the AVR9 elicitor protein. The extracellular leucine-rich repeats are required for the specificity of the elicitor protein recognition. Belongs to the RLP family. In cv. LA101, 9DC1 results from the rearrangement in the Cf-9 disease resistance gene cluster between Cf-9 and Hcr9-9D, both originating from the cv. Cf9.