This article analyses the linguistic and multimodal interactions of a group of seven cancer patients and two carers, who had previously met on a residential course and subsequently set up an online support group. I explore how this group of participants constructs relationships of support and solidarity online over 7 months using a range of multimodal resources including web links, video clips, avatars and songs. This is a semi-ethnographic case study that arose from my own experiences as a participant in the support group. I gathered the data directly from the WhatsApp facility on a 'smartphone' and then analysed the interactions and their use of diverse resources by means of Interactional Sociolinguistics analysis. The article finds that participants construct support and solidarity in highly inventive ways: by using diverse modes and types of expression, by means of humour, building a 'special' sense of in-group togetherness, and biographical work, that is, recasting 'who they are' in light of their illness.