Sir,I am delighted that authors have shown keen interest in the case report published in the journal.[1] Radiation in our case definitely caused alteration in the local immune response the so-called “immunocompromised cutaneous district,” which led to the development of morphea. The authors have thrown light on the mechanism, by which immune dysregulation occurs in the irradiated areas. Altered trafficking of immune competent cells, lymphatic obstruction, and interference in neurotransmitter signaling, all lead to immune disorders such as morphea. The term isotopic response first described by Wolf et al.[2] refers to occurrence of a new skin disorder at the site of another, unrelated, and already healed skin disease.[2] The localization of skin diseases remains one of the most elusive problems in dermatology.[2] Etiology of isotopic response is thought to be immunologic, neural, vascular, viral, and locus minoris resistentiae (a site of lessened resistance).[3] The concept of isoradiotopic response as described and categorized by Caccavale et al.[4] does hold good in our case. More literature review is needed to consider it a new form of isotopic response.